1. The accompanying figure is a graph of an object’s position as a function of time.

 

Which lettered segment corresponds to a time when the object has a negative acceleration?

2. A car is moving at a constant velocity to the right along a straight level highway. Just as the car passes a cliff, a rock falls straight down in the cliff’s reference system. Which of the accompanying curves best depicts the path the rock takes in the car’s reference system?

3. Three blocks – 1, 2, and 3 – rest on a horizontal frictionless surface, as shown in the accompanying figure. Each block has a mass m, and the blocks are connected by massless strings. Block 3 is pulled to the right by a force F.

 

 

The resultant force on block 2 is:

4. Which solid vector in the accompanying figures best represents the acceleration of a pendulum mass at an intermediate point in its swing?

5. A mass attached to a horizontal massless spring is displaced 16 cm to the right of its equilibrium position and released from rest. At its 16 cm extension, the spring-mass system has 1.28 joules of potential energy.

 

Upon release, it slides across a rough surface and comes momentarily to rest 8 cm to the left of its equilibrium position. How much mechanical energy was dissipated by friction?

6. Two identical masses m are connected to a massless string which is hung over two frictionless pulleys as shown.

 

If everything is at rest, what is the tension in the cord?

14. A heavy rod of length L and weight W is suspended horizontally by two vertical ropes as shown below. The first rope is attached to the left end of the rod while the second rope is attached a distance ¼L from the right end.

 

The tension in the second rope is: