Physics Book - User contributions [en]

Current

2015-12-06T00:55:52Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>

<math>i=density⋅volume/seconds =nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>

The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be <math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = |q|nAv</math>

<math>i = nAv</math>

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
One type of problem you are sure to encounter involves a battery and resistor. You can read more about that section on the RC page of this wiki, but here's how to solve one now:

Using your formula sheet, notice that <math>I = {|ΔV|\over R}</math>. where R is the resistance in the circuit and |ΔV| is the voltage.

If you're given that the 50V battery is connected to a 100 <math>Ω</math> resistor, you simply substitute the values into your equation.
<math>I = {50V\over 100 Ω}</math>
<math>I = 0.5A</math>
===Middling===
Current will not always be what you solve for, though. In this problem, let's use the equations we've discussed to find the drift velocity <math>v</math>.
Given the current is <math>1A</math>, the electron density is <math>8 ⋅ 10^{27}m^{-3}</math>, and the diameter of our wire is <math>1mm</math>.

First, let's find the area <math>{0.001\over 2}^{2}⋅π=7.85⋅10^{-7}</math>

Then, plug in the rest: <math>1=|-1.6⋅10^{-19}|⋅5⋅10^{28}⋅7.85⋅10^{-7}⋅v, v = 9.9477.85⋅10^{-4}{m\over s}</math>

==References==
https://en.wikipedia.org/wiki/Electric_current

http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-06T00:26:06Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>

<math>i=density⋅volume/seconds =nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = |q|nAv</math>

<math>i = nAv</math>

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
One type of problem you are sure to encounter involves a battery and resistor. You can read more about that section on the RC page of this wiki, but here's how to solve one now:

Using your formula sheet, notice that <math>I = {|ΔV|\over R}</math>. where R is the resistance in the circuit and |ΔV| is the voltage.

If you're given that the 50V battery is connected to a 100 <math>Ω</math> resistor, you simply substitute the values into your equation.
<math>I = {50V\over 100 Ω}</math>
<math>I = 0.5A</math>
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-06T00:16:38Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>

<math>i=density⋅volume/seconds =nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = |q|nAv</math>

<math>i = nAv</math>

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:59:59Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>

<math>i=density⋅volume/s=nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = NqAv</math>

<math>i = nAv</math>

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:58:04Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>

<math>i=density⋅volume/s=nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = NqAv</math>

<math>i = nAv</math>

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:57:33Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>
<math>i=density⋅volume/s=nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = NqAv</math>

<math>i = nAv</math>

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:57:05Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density <math>n</math> of electrons (uniform current) in a wire of area <math>A</math>
<math>i=density⋅volume/s=nA v</math>

If a charge distribution of density <math>ρ</math> moves with the velocity <math>v</math>, the charge per unit time through <math>ΔA</math> is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then <math>ρv⋅nΔS</math>, from which we get the current density to be<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = NqAv</math>

<math>i = nAv</math>

<math>I = |q|nA</math>
===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:55:12Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density n of electrons (uniform current) in a wire of area A
<math>i=density⋅volume/s=nA v</math>

If a charge distribution of density ρ moves with the velocity v, the charge per unit time through ΔA is <math>ρv⋅nΔA</math>
<math>Δq=ρv⋅nΔAΔt</math>.
<math>ρ = Nq</math>
The charge per unit time is then ρv⋅nΔS, from which we get the current density to be
<math>Nqv</math>

The current I through the surface is <math>I=∫Nqv⋅dA</math>

<math>I = NqAv</math>

<math>i = nAv</math>
<math>I = | q | n A </math>
n=density of electrons

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:53:27Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density n of electrons (uniform current) in a wire of area A
i=density⋅volume/s=nA v

If a charge distribution of density ρ moves with the velocity v, the charge per unit time through ΔA is ρv⋅nΔA
Δq=ρv⋅nΔAΔt.
ρ = Nq
The charge per unit time is then ρv⋅nΔS, from which we get the current density to be
Nqv

The current I through the surface is <math>I=∫\sum_{surface} \Nqv⋅dA</math>

<math>I = NqAv</math>

i = n A v
I = | q | n A v
n=density of electrons

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-05T23:46:45Z

Spencer: /* A Mathematical Model */

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density n of electrons (uniform current) in a wire of area A
i=density⋅volume/s=nA v

If a charge distribution of density ρ moves with the velocity v, the charge per unit time through ΔA is ρv⋅nΔA
Δq=ρv⋅nΔAΔt.
ρ = Nq
The charge per unit time is then ρv⋅nΔS, from which we get the current density to be
Nqv

The current I through the surface is I=∫Nqv⋅dA

<math>I = NqAv</math>

i = n A v
I = | q | n A v
n=density of electrons

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-01T01:57:42Z

Spencer:

Claimed by spencer

Explanation of Current Through a Wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high to low energy.

===A Mathematical Model===

Assume uniform density n of electrons (uniform current) in a wire of area A
i=density⋅volume/s=nA v

If a charge distribution of density ρ moves with the velocity v, the charge per unit time through ΔA is ρv⋅nΔA
Δq=ρv⋅nΔAΔt.
ρ = Nq
The charge per unit time is then ρv⋅nΔS, from which we get the current density to be
Nqv

The current I through the surface is I=∫Nqv⋅dA

I = NqAv

i = n A v
I = | q | n A v
n=density of electrons

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-01T01:55:29Z

Spencer:

Current

2015-12-01T01:54:13Z

Spencer:

Claimed by spencer

Explanation of Current through a wire

==The Main Idea==
The electric current is the continual flow of electric charge through an area. In a wires you will be studying, the current is constant regardless of its width and diameter. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the particles may be moving however they please, but their net drift velocity stays constant. The most common charge carrier you will encounter is negative. While the positive charge can be the mover, in almost all metals the current consists of drifting electrons. The direction the electrons flow is not the same as the conventional current, however. Before scientists knew that electrons were the common charge carriers, they discovered current. And, with only two choices, they chose to treat the moving charge as positive. This may seem annoying at first, but there are some benefits to using conventional current over the directly opposed "electron current". For one, it flows from the positive end of a battery toward the negative end, and from high energy to low energy.

===A Mathematical Model===

What are the mathematical equations that allow us to model this topic. For example <math>{\frac{d\vec{p}}{dt}}_{system} = \vec{F}_{net}</math> where '''p''' is the momentum of the system and '''F''' is the net force from the surroundings.

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elecur.html

[[Category:Which Category did you place this in?]]

Current

2015-12-01T01:35:30Z

Spencer:

Claimed by spencer

Explanation of Current through a wire

==The Main Idea==
The electric current is the flow of electric charge through an area. It is important to note that the charge in the circuits you will be dealing with are not in equilibrium, but instead, in a steady state. The distinction and the circuits state become clear when you remember that a metal in equilibrium contains no mobile charge in motion. Since there is flow (motion) with a current, the velocity cannot be zero, and equilibrium is not the current state. In a steady state, the electrons may be moving however they please, but their average drift velocity stays constant.

===A Mathematical Model===

What are the mathematical equations that allow us to model this topic. For example <math>{\frac{d\vec{p}}{dt}}_{system} = \vec{F}_{net}</math> where '''p''' is the momentum of the system and '''F''' is the net force from the surroundings.

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==References==
https://en.wikipedia.org/wiki/Electric_current
http://www.feynmanlectures.caltech.edu/II_13.html#Ch13-S2

[[Category:Which Category did you place this in?]]

Current

2015-11-03T03:58:51Z

Spencer:

Claimed by spencer

Short Description of Topic

==The Main Idea==

State, in your own words, the main idea for this topic
Electric Field of Capacitor

===A Mathematical Model===

What are the mathematical equations that allow us to model this topic. For example <math>{\frac{d\vec{p}}{dt}}_{system} = \vec{F}_{net}</math> where '''p''' is the momentum of the system and '''F''' is the net force from the surroundings.

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==Connectedness==
#How is this topic connected to something that you are interested in?
#How is it connected to your major?
#Is there an interesting industrial application?

==History==

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

== See also ==

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

===Further reading===

Books, Articles or other print media on this topic

===External links===

Internet resources on this topic

==References==

This section contains the the references you used while writing this page

[[Category:Which Category did you place this in?]]

Current

2015-11-03T03:57:50Z

Spencer: Created page with "Short Description of Topic ==The Main Idea== State, in your own words, the main idea for this topic Electric Field of Capacitor ===A Mathematical Model=== What are the mat..."

Short Description of Topic

==The Main Idea==

State, in your own words, the main idea for this topic
Electric Field of Capacitor

===A Mathematical Model===

What are the mathematical equations that allow us to model this topic. For example <math>{\frac{d\vec{p}}{dt}}_{system} = \vec{F}_{net}</math> where '''p''' is the momentum of the system and '''F''' is the net force from the surroundings.

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==Connectedness==
#How is this topic connected to something that you are interested in?
#How is it connected to your major?
#Is there an interesting industrial application?

==History==

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

== See also ==

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

===Further reading===

Books, Articles or other print media on this topic

===External links===

Internet resources on this topic

==References==

This section contains the the references you used while writing this page

[[Category:Which Category did you place this in?]]

Main Page

2015-11-03T03:57:34Z

Spencer:

__NOTOC__
Welcome to the Georgia Tech Wiki for Intro Physics. This resources was created so that students can contribute and curate content to help those with limited or no access to a textbook. When reading this website, please correct any errors you may come across. If you read something that isn't clear, please consider revising it!

Looking to make a contribution?
#Pick a specific topic from intro physics
#Add that topic, as a link to a new page, under the appropriate category listed below by editing this page.
#Copy and paste the default [[Template]] into your new page and start editing.

Please remember that this is not a textbook and you are not limited to expressing your ideas with only text and equations. Whenever possible embed: pictures, videos, diagrams, simulations, computational models (e.g. Glowscript), and whatever content you think makes learning physics easier for other students.

== Source Material ==
All of the content added to this resource must be in the public domain or similar free resource. If you are unsure about a source, contact the original author for permission. That said, there is a surprisingly large amount of introductory physics content scattered across the web. Here is an incomplete list of intro physics resources (please update as needed).
* A physics resource written by experts for an expert audience [https://en.wikipedia.org/wiki/Portal:Physics Physics Portal]
* A wiki book on modern physics [https://en.wikibooks.org/wiki/Modern_Physics Modern Physics Wiki]
* The MIT open courseware for intro physics [http://ocw.mit.edu/resources/res-8-002-a-wikitextbook-for-introductory-mechanics-fall-2009/index.htm MITOCW Wiki]
* An online concept map of intro physics [http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html HyperPhysics]
* Interactive physics simulations [https://phet.colorado.edu/en/simulations/category/physics PhET]
* OpenStax algebra based intro physics textbook [https://openstaxcollege.org/textbooks/college-physics College Physics]
* The Open Source Physics project is a collection of online physics resources [http://www.opensourcephysics.org/ OSP]
* A resource guide compiled by the [http://www.aapt.org/ AAPT] for educators [http://www.compadre.org/ ComPADRE]

== Organizing Catagories ==
These are the broad, overarching categories, that we cover in two semester of introductory physics. You can add subcategories or make a new category as needed. A single topic should direct readers to a page in one of these catagories.

<div class="toccolours mw-collapsible mw-collapsed">
===Interactions===
<div class="mw-collapsible-content">
*[[Fundamental Interactions]]
*[[System & Surroundings]]

</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Theory===
<div class="mw-collapsible-content">
*[[Einstein's Theory of Relativity]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Properties of Matter===
<div class="mw-collapsible-content">
*[[Mass]]
*[[Charge]]
*[[Spin]]
*[[SI Units]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Contact Interactions===
<div class="mw-collapsible-content">
* [[Young's Modulus]]
* [[Friction]]
* [[Tension]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Momentum===
<div class="mw-collapsible-content">
* [[Vectors]]
* [[Kinematics]]
* Predicting Change in one dimension
* [[Predicting Change in multiple dimensions]]
* [[Momentum Principle]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Angular Momentum===
<div class="mw-collapsible-content">
* [[The Moments of Inertia]]
* [[Rotation]]
* [[Torque]]
* Predicting a Change in Rotation
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Energy===
<div class="mw-collapsible-content">
*Predicting Change
*[[Rest Mass Energy]]
*[[Kinetic Energy]]
*[[Potential Energy]]
*[[Work]]
*[[Thermal Energy]]
*[[Conservation of Energy]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Fields===
<div class="mw-collapsible-content">
* [[Electric Field]] of a
** [[Point Charge]]
** [[Electric Dipole]]
** [[Capacitor]]
** [[Charged Rod]]
** [[Charged Disk]]
** [[Charged Spherical Shell]]
*[[Electric Potential]]
**[[Potential Difference in a Uniform Field]]
*[[Magnetic Field]]
**[[Direction of Magnetic Field]]
**[[Bar Magnet]]
**[[Magnetic Force]]
**[[Hall Effect]]
**[[Lorentz Force]]
**[[Biot-Savart Law]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Simple Circuits===
<div class="mw-collapsible-content">
*[[Components]]
*[[Steady State]]
*[[Non Steady State]]
*[[Node Rule]]
*[[Loop Rule]]
*[[Power in a circuit]]
*[[Ammeters,Voltmeters,Ohmmeters]]
*[[Current]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Maxwell's Equations===
<div class="mw-collapsible-content">
*[[Gauss's Flux Theorem]]
**[[Electric Fields]]
**[[Magnetic Fields]]
*[[Faraday's Law]]
*[[Ampere-Maxwell Law]]
</div>
</div>

<div class="toccolours mw-collapsible mw-collapsed">

===Radiation===
<div class="mw-collapsible-content">
</div>
</div>

== Resources ==
* Commonly used wiki commands [https://en.wikipedia.org/wiki/Help:Cheatsheet Wiki Cheatsheet]
* A guide to representing equations in math mode [https://en.wikipedia.org/wiki/Help:Displaying_a_formula Wiki Math Mode]
* A page to keep track of all the physics [[Constants]]
* An overview of [[VPython]]