Question

A ball of mass 0.50 kg moving at a speed of 5.0 $\frac{m}{s}$ collides with another ball of mass 1.0 kg .After the collision the balls stick together and remain motionless.What was the velocity of the 1.0 kg block before the collision?

Answer 1

Mass of the ball,$m_1=0.5kg$,

Velocity of the ball=5.0 $\frac{m}{s}$

Mass of the another ball=$m_2=1kg$

Let its velocity=$v_1\frac{m}{s}$

Using law of conservation of momentum $0.5\times 5+1\times v^1=0$
$\Rightarrow v^1=-2.5$

$\therefore$ Velocity of second ball is $2.5\frac{m}{s}$ opposite of the direction of motion of 1st ball.