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Homework 4
Assigned: 9/19/17 Week 5
Due : Week 6 in recitation
1. A line of charge extends from the origin to x=L. The total charge on the line is Q. What is the electric field at a point x=-a?
2. Derive an expression for the electric field for a charged disk of uniform charge density at a point P above the plane of the disk. Be prepared to explain the steps involved in the derivation.
3. Using Gauss' law obtain the expression for an infinite line of charge.
4. Find the potential at the origin due to three charges. Where q1=.03C, r1=(1,2,0), q2= -.05C, r2=(1,-3,0), q3=.01C, r3=(1,-2,0).
5. Calculate the work done on an electron that moves through a potential difference of 1V. This energy defines what we call and electron volt or eV.
6. Calculate the potential 2m away from a 2 microcoulomb charge.
7. Calculate how close a moving -3.6 microcoulomb charge gets to a fixed -2.0 microcoulomb charge if it is fired at the fixed charge from a distance of 5 cm away. At first it is moving at 70 m/s. IT HAS A MASS OF 1g.
8. Calculate the electric potential at (1,1) if there are charges 1.2, -2.3, 1.0 micro coulombs at (1,0), (0,0), and (0,1). Distances are in meters. Calculate the electric potential energy of the configuration in the problem.
9. Calculate the potential at the point x=-a, due to a line of charge with total charge Q and with endpoint at (0,0) and (L,0).
10. What is the potential difference between going from point (1,0) to (3,0) along the x axis in an electric field E=3x^2 i.
11. Calculate the electric field due to a potential, V = 3xy-5x^2-2z^3xy.
12. For a 2 microcoulomb charge at the origin and a 3 microcoulomb charge at x=17 cm, where on the x axis between them is the electric potential the smallest?