Question

A 2 kg ball of putty moving to the right at 3 m/s has a perfectly inelastic, head-on collision with a 1 kg ball of putty moving at 2 m/s. What is the final magnitude and direction (left or right) of the velocity of the balls after the collision?

Answer 1

Answer:

$V=1.33m/s$   to the right

Explanation:

The balls collide in a completely inelastic collision, in other words they have the same velocity after the collision, this velocity has a magnitude V.

We need to use the conservation of momentum Law, the total momentum is the same before and after the collision.

In the axis X:

$m_{1}*v_{o1}-m_{2}*v_{o2}=(m_{1}+m_{2})V$     (1)

$V=(m_{1}*v_{o1}-m_{2}*v_{o2})/(m_{1}+m_{2})=(2*3-1*2)/(2+1)=1.33m/s$