1. Objects A and B each have mass m. Each is traveling at speed v and in the opposite direction from the other object. As explained by the law of conservation of momentum, which event could not occur after the two objects collide?
Both objects reverse direction, each traveling at v.
Both objects stick together, each motionless.
Both objects reverse direction, one traveling at 0.5v and the other at 2v.
Both objects reverse direction, each traveling at 0.5v.
2. An ore cart of mass 1200 kg is rolling at a speed of 10.8m/s across a flat surface. A crane dumps ore into the cart from directly above it, after which the cart travels at 9.3 m/s. What mass of ore did the crane add to the cart? Assume that frictional forces with the flat surface are negligible.
240 kg
190 kg
110 kg
92 kg
3. As shown in the diagram, a bullet of mass 7.0 g strikes a block of wood of mass 2.1 kg. The block of wood is suspended by a string of length 2.0 m, forming a pendulum. The bullet lodges in the wood, and together they swing upward a distance of 0.40 m from the original position of the wood block. What was the speed of the bullet just before it struck the wooden block?
840 m/s
720 m/s
590 m/s
690 m/s
750 m/s
4. A block of mass m = 4.8 kg slides from left to right across a frictionless surface with a speed Vi=7.3m/sIt collides with a block of mass M = 11.5 kg that is at rest. After the collision, the 4.8-kg block reverses direction, and its new speed is vf=2.5m/s. What is V, the speed of the 11.5-kg block?
6.5 m/s
4.1 m/s
5.6 m/s
4.7 m/s
3.7 m/s
