Question

Two balls of the same density, one large and one small, roll toward each other at the same speed. When they collide, what will happen to the larger ball?

a.)it will be propelled backward
b.)it will jump over the smaller ball
c.)it will continue forward
d.)it will stop

Answer 1

The outcome of the collision between two balls of the same density but different sizes depends on their mass and the type of collision. If the collision is perfectly elastic and the balls have the same mass, they may come to a stop. Otherwise, the larger ball may continue moving forward if the collision is inelastic.

Step-by-step explanation:

When two balls of the same density and the same speed collide, the outcome depends on their masses. If they have the same mass, they should exchange velocities, but because their speeds are the same, they both should come to a stop if the collision is perfectly elastic. However, if the collision is inelastic and the balls stick together, their combined center of mass velocity post-collision will be zero.

In the case of balls of different sizes (but same density) colliding, if they are rolling towards each other at the same speed, and we assume the larger ball has more mass, then the momentum conservation principle tells us that after the collision, the larger ball will continue moving forward to some degree, while the smaller ball will either slow down, stop, or move backward depending on the types of collision (elastic or inelastic). However, without the specifics of the masses or the type of collision (elastic or inelastic) we cannot determine the exact final velocities of the balls.