course PHY 202 ??J{??????y??assignment #004004.
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17:23:03 Query introductory set #1, 10-17 Explain how to find the potential difference in volts between two given points on the x axis, due to a given charge at the origin.
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RESPONSE --> The potential difference between two points due to a given charge at the origin can be calculated by using the formua: -Wba/q. Where -W is the work negative work done to move a charge from point a to b. q represents the charge at the origin. confidence assessment: 2
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17:32:09 ** Potential difference is the work per Coulomb of charge moved between the two points. To find this work you can multiply the average force on a Coulomb of charge by the displacement from the first point to the second. You can find an approximate average force by finding the force on a 1 Coulomb test charge at the two points and averaging the two forces. Multiplying this ave force by the displacement gives an approximate potential difference. Since the force is not a linear function of distance from the given charge, if the ratio of the two distances from the test charge is not small the approximation won't be particularly good. The approximation can be improved to any desired level of accuracy by partitioning the displacement between charges into smaller intervals of displacement and calculating the work done over each. The total work required is found by adding up the contributions from all the subintervals. University Physics students should understand how this process yields the exact w ""ork, which is the integral of the force function F(x) = k Q / x^2 between the two x values, yielding total work W = k * Q * 1 Coulomb ( 1 / x1 - 1 / x2) and potential difference V = k * Q ( 1 / x1 - 1 / x2). **
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RESPONSE --> It seems like the formula that I gave -Wba/q, is an easier way to find the potential difference. The solution did help me understand that the potential difference is the work per Coulumb of charge moved between two points. But the method of finding the average force between the two forces doesn't seem useful because you will calculate an ""approximate"" potential difference. self critique assessment: 2
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17:34:37 Explain how to find the potential difference between two points given the magnitude and direction of the uniform electric field between those points.
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RESPONSE --> If I was given the uniform electrical field between two points, I would use the formula: -qEd. Where q is the test charge, E is the mag of the electrical field and d is the displacement between thos e two points. confidence assessment: 3
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17:35:04 ** The work per Coulomb done between the two points is equal to the product of the electric field E and the displacement `dr. Thus for constant field E we have V = E * `dr. **
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RESPONSE --> ok self critique assessment: 3
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17:40:21 Explain how to find the average electric field between two points given a specific charge and the work done on the charge by the electric field as the charge moves between the points.
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RESPONSE --> The average strength of an electrical field is the average force per unit of charge. So the first step is to find the average force between the two points, which can be found by using the formula:-W=Fd Where W is the work done, and d is the displacement. Solve for F. Since the strength of the electrical field is the average force per unit of charge, you divide magnitude of F by the given charge. confidence assessment: 3
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17:42:02 ** You get ave force from work and distance: F_ave = `dW / `ds. You get ave electric field from work and charge: E_ave = F / q. An alternative: Find potential difference `dV = `dW / q. Ave electric field is Eave = `dV / `ds **
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RESPONSE --> ok self critique assessment: 3
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17:45:20 In your own words explain the meaning of voltage.
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RESPONSE --> Voltage or a ""volt"" is the unit of measurement for electric potential or the potential difference.It represents joules/coulomb. Expressed in another way, it's the electrical potential energy per unit charge. confidence assessment: 3
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17:45:35 ** Voltage is the work done per unit of charge in moving charge from one point to another. **
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RESPONSE --> ok self critique assessment: 3
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???Q???????????? assignment #004 004. Physics II 06-12-2007"