The velocity of light (c) is 3 x 108 m/s

1. Assume that you weigh a book on an equal-arm balance while an elevator is stopped at the ground floors. Would you get the same result if the elevator were accelerating upward? Explain you reasoning.

2. An aircraft carrier is the moving to the north at a constant 25 mph on a windless day. A plane requires a speed relative to the air of 125 mph to take off. How fast must the plane be traveling relative to the deck of the aircraft carrier to take off if the plane is headed (a) north? (b) South?

3. Mitch, in Question 13, has just returned from physics class where he was studying about work. Mitch argues that, from his frame of reference, Gary applies 600-newton force for a distance of 20 meters in 1 second and therefore does 12,000 joules of work on the block. He wonders why the block does not appear to speed up as a result of this work. What is the flaw in Mitch's reasoning?

4. Assume that you are driving down a straight road at a constant speed. A helium-filled balloon is tied to a string that is pinned to the front seat. Which way will the balloon swing when you apply the brakes? Explain your reasoning.

5. What does the scale read if a 5-kg cat lies on a bathroom scale in an elevator accelerating downward at 0.2g?

6. You hold a charged rubber rod near the ball of an electroscope and then briefly touch the ball with your finger. After removing the rubber rod, you bring a charged glass rod near the ball. Will the deflection of the leaves increase, decrease, or stay the same? Why?

7. Two identical charges are fixed at the locations indicated in the following figure. A third charge, identical to the other two, is placed first at position A and then position B. For each case, determine the direction of the net electrical force on the third charge. If the force is zero, state that explicitly.

8. For the situation described in Question 49, the charged particle is released from rest at the midpoint and strikes the negative place at speed v if the particle had instead been released from rest at point A, would it have struck the negative plate at a speed greater than, equal to, or less than v? Explain your reasoning.

9. By what distance must two charges of +2C and +8C be separated so that the repulsive force between them is 3.6 X 10^10 N?

10. What is the electric filed 5.3 X 10^-11 m from a proton?

1) Michelson used a rotating eight-sided mirrored "wheel" to determine the speed of light. In this case, the mirror is rotated at a certain frequency which allows the light to travel from the source, reflect off the mirrored "wheel" towards a stationary mirror some distance away, to be reflected back to the rotating octagonal mirrored wheel and thence into the observers eye. What is the minimum frequency of rotation for this to happen if the distance from the fixed mirror to the rotating one is 35.4 km?

2) Two identical boats travel through still water at 3 m/s. They start from the same point on the bank of a river and travel the same distance from the starting point and then return to the starting point. One boat takes a path parallel (and anti parallel) to the current while the other has a path that is perpendicular to the current. It takes one boat twice as long as the other boat. How fast is the current in the river flowing?