Question

A ball of mass 0.25kg loses one third of it's velocity on collision with an identical ball 9/2 at rest after collision q moves off with a speed of 2m/s in the original direction of p. Calculate the original velocity of p.

Answer 1

Explanations & Calculations

• Say the initial velocity of the ball P is $\small V$ then apply conservation of linear momentum to the system of 2 balls along the direction of P.

$\qquad\qquad \begin{aligned} \small \to\\ \small mV+0&=\small m.\frac{V}{3}+m\times2\\ \small V&=\small \frac{V}{3}+2\\ \small V&=\small 3\,ms^{-1} \end{aligned}$