Question

Two billiard balls $A$ and $B$, each of mass $50g$ moving in opposite directions with speed of $5m{s}^{-1}$ each, collide and rebound with the same speed. If the collision lasts for ${10}^{-3}s$, which of the following statements are true?

• A. The impulse imparted to each ball is $0.25kgm{s}^{-1}$ and the force on each ball is $250N$.
• B. The impulse imparted to each ball is $0.25kgm{s}^{-1}$ and the force exerted on each ball is $25\times {10}^{-5}N$
• C. The impulse imparted to each ball is $0.5N-s$
• D. The impulse and the force on each ball are equal in magnitude and opposite in directions

Answer 1

The correct option is A The impulse imparted to each ball is $0.25kgm{s}^{-1}$ and the force on each ball is $250N$.

In this problem first we have to decide the direction of motion. Let block A moves up the plane friction force on A will be downward (along the plane) as shown.

On putting the value in the above equation we get the impulse imparted to each ball is 0.25 kg ms−1 and the force on each ball is 250 N.