2. A student wants to make a model to show how friction works. Which of the following ideas best demonstrates friction? O A. Pour water into a cup and then slowly pour it out again.
O B. Bounce a rubber ball up and down on an icy surface.
OC. Drop a heavy rock from a large distance down onto modeling clay.

OD. Wrap tape with sticky side out around a ball and roll it along a surface.
3. The force that prevents a ball rolling on the ground from continuing on its path forever is:
O A. inertia
OB. momentum.
O c. friction.
OD. kinetic energy.
4. Friction acts between two metal blocks that slide past each other. Why would a coating of oil between the two blocks
reduce the friction?
O A. The oil increases the surface contact between the two blocks.
OB. The oil decreases the speed at which the two blocks can slide.
OC. The oil fills in tiny spaces so the sliding surfaces are smoother.
OD. The oil makes the surfaces stickier so that the sliding speed increases.
5. Friction causes the kinetic energy of a rolling ball to be converted into:
O A. momentum.
B. heat energy.
C. inertia.
OD. chemical energy.

30 POINTSS