A heavy steel ball of mass greater than $1\, kg$ moving with a speed of 2$m\,{\sec ^{ - 1}}$collides head on with a stationary ping-pong ball of mass less than $0.1\, gm$. The collision is elastic. After the collision the ping-pong ball moves approximately with speed ......... $m\,{\sec ^{ - 1}}$
A heavy steel ball of mass greater than $1\, kg$ moving with a speed of 2$m\,{\sec ^{ - 1}}$collides head on with a stationary ping-pong ball of mass less than $0.1\, gm$. The collision is elastic. After the collision the ping-pong ball moves approximately with speed ......... $m\,{\sec ^{ - 1}}$
$2$
$4$
$2 \times {10^4}$
$2 \times {10^3}$
A heavy steel ball of mass greater than $1\, kg$ moving with a speed of 2$m\,{\sec ^{ - 1}}$collides head on with a stationary ping-pong ball of mass less than $0.1\, gm$. The collision is elastic. After the collision the ping-pong ball moves approximately with speed ......... $m\,{\sec ^{ - 1}}$
We know that when heavier body strikes elastically with a lighter body then after collision lighter body will move with double velocity that of heavier body.
i.e.the ping pong ball move with speed of $2 \times 2 = 4\;m/s$