Question

A massive ball moving with a speed $v$ collide with a tiny ball having a very small mass , immediately after the impact the second ball will move at speed approximately equal to :

• A. $\infty$
• B. $\frac{v}{2}$
• C. $v$
• D. $2v$

Answer 1

Answer: (D)

$2v$

In an elastic collision where the projectile is much more massive than the target, the velocity of the target particle after the collision will be about twice that of the projectile and the projectile velocity will be essentially unchanged. Hence, the second ball will move at a speed approximately equal to $2v$.