1. You are the captain of a spaceship. You need to measure the electric field in space in the vicinity of the spaceship. You send a crew member outside with a meter stick, a stopwatch, and a small ball (of known mass M and net charge Q (held by insulating strings while being carried). You must explain to the crew member what observations of the ball to make for you, and explain how you will use those observations to determine the magnitude and direction of the electric field at location P.

a) List the data the crew member must obtain.
b) Give the formula(s) you must use to obtain the electric field from these data.

2. a. Find the net force in vector form on the -6 C object in the diagram below.
b. Find the magnitude and direction of this force.

3. What is the work required to move a 2 C charge from A to B in the figure below?

4. a. Find the system of equations that will obtain current in each of the resistors in the figure below.

5. The segment of conductor shown in the figure at right carries a current I = 0.2 A. The shorter section is 0.8 m long, and the longer section is 1.6 m long. Determine the magnitude and direction of the magnetic force on the conductor if there is a uniform magnetic field given by B = 2i over the region.

6. a. Find the direction of the current in the resistor R when the magnet is dropped from above just after it has passed through the ring.

b. Find the direction of the current in the resistor R just after the switch is opened.

7. A battery establishes a steady current around the circuit illustrated below. Compass needles are placed successively at points A, B, and C along the circuit.

The relative deflection of the compass needles, in descending order, is (circle the correct answer):

1. A, B, then C

2. B, C, then A

3. C, B, then A

4. B, C, then A

5. B, A, then C

8. Here is a circuit consisting of two flashlight batteries, a large air-gap capacitor, a nichrome wire, and thick copper wires. The circuit is allowed to run long enough that the capacitor is fully charged with +Q and -Q on the plates.

a. Which direction does the current flow when you pull the two plates further apart ?

b. How do you know?

9. a. If V_R = E_D - I_R r, and V_R = I_R R, eliminate I_R from these two equations and express V_R as a function of R.

b. Power PR = V_R 2 / R. Express P_R as a function of R and then find the derivative dP_R / dR

10. An underwater diver sees the sun at an apparent angle of 45° from the vertical. What is the actual angle of the Sun above the horizon?

11. A spherical convex mirror has a radius of curvature of 40 cm. The object is 30 cm in front of the mirror.
a. Draw the ray diagram .

b. Determine the position of the virtual image and the magnification.

12. A convex thin lens has a focal length of 25 cm . The object is placed at 26 in front of the lens.
a. Draw the ray diagram.

b. Determine the location of the image and the magnificaiton.