Question

As per the given figure, a small ball $P$ slides down the quadrant of a circle and hits the other ball $Q$ of equal mass which is initially at rest Neglecting the effect of friction and assume the collision to be elastic, the velocity of ball $Q$ after collision will be :$\left( g =10 \,m / s ^2\right)$

• A. $4\, m / s$
• B. 0
• C. $0.25 \,m / s$
• D. $2\, m / s$

Answer 1

Answer: (D)

$2\, m / s$

Answer 2

The velocities will be interchanged after collision.
Speed of P just before collision =2gh​
=2×10×0.2​=2m/s