Question

A 2.10-kg block is moving to the right at 2.00 m/s just before it strikes and sticks to a 1.00-kg block initially at rest. What is the total momentum of the two blocks after the collision? Enter a positive answer if the total momentum is toward right and a negative answer if the total momentum is toward left. Kg m/s

Answer 1

Given,

The mass of the moving block, M=2.10 kg

The velocity of the moving block, u=2.00 m/s

The mass of the block that was at rest, m=1.00 kg

The velocity of the second block before the collision, v=0 m/s

From the law of conservation of momentum, the total momentum of a system always remains constant. That is, the total momentum of the two blocks before the collision is equal to the total momentum of the blocks after the collision.

Therefore, the total momentum of the two blocks after the collision is given by,

`p=Mu+mv`

On substituting the known values,

`\begin{gathered} p=2.10*2.00+1.00*0 \\ =4.2\text{ kg. m/s} \end{gathered}`

Therefore, the total momentum of the blocks after the collision is 4.2 kg· m/s