Question

two wooden balls collide in the air while a man is juggling them. how does the total momentum within the system of the two balls change after the collision? a. the balls experience no change in total momentum because momentum is conserved. b. the balls experience an increase in total momentum because their combined mass is greater. c. the balls experience a decrease in total momentum because colliding causes them to slow down. d. the balls experience a complete conversion of momentum to potential energy after their collision.

Explanation:

To determine the change in total momentum of the two - ball system during collision, we refer to the law of conservation of momentum. The law states that in a closed system (a system where the net external force is zero), the total momentum before an event (like a collision) is equal to the total momentum after the event. In the case of the two wooden balls being juggled, the system of the two balls can be considered (we can neglect external forces like air resistance for the purpose of understanding the conservation of momentum in the collision itself).

• Option A: According to the law of conservation of momentum, the total momentum of a closed system remains constant. During the collision of the two balls, the forces they exert on each other are internal forces. So the total momentum of the system of the two balls should be conserved, meaning there is no change in total momentum.
• Option B: The total momentum of a system depends on the mass and velocity of the objects in the system. The combined mass of the two balls doesn't change just because they collide, and momentum conservation tells us that the total momentum should remain the same, not increase. So this option is incorrect.
• Option C: Even if the balls slow down relative to each other during the collision, the total momentum of the system (which takes into account the momentum of both balls) remains constant. The momentum lost by one ball is gained by the other ball due to the internal forces of collision. So there is no decrease in total momentum, and this option is wrong.
• Option D: Momentum and energy are different physical quantities. Momentum is not converted to potential energy in a collision (at least not completely). In a collision, kinetic energy may be converted to other forms of energy like heat or sound, but momentum is conserved separately. So this option is incorrect.

Answer:

A. The balls experience no change in total momentum because momentum is conserved.