Chapter 3, Problem 55R

To determine

The momentum of the wooden ball after the collision.

Answer to Problem 55R

The momentum of the wooden ball after the collision is $4\text{kg}\cdot \text{m}/\text{s}$ .

Explanation of Solution

Given info:

Momentum of the wooden ball before the collision, $P_{w,i}=0\text{kg}\cdot \text{m}/\text{s}$

Momentum of the metal ball before the collision, $P_{m,i}=6\text{kg}\cdot \text{m}/\text{s}$

Momentum of the metal ball after the collision, $P_{m,f}=2\text{kg}\cdot \text{m}/\text{s}$

Formula used:

The expression to determine the momentum of wooden ball after collision using the conservation of momentum is,

  $P_{m,i}+P_{w,i}=P_{m,f}+P_{w,f}$

Here,

• $P_{w,f}$ is momentum of the wooden ball after the collision.

Calculation:

Substitute the given values in the above equation.

  $\begin{array}{c}{P}_{m,i}+P_{w,i}=P_{m,f}+P_{w,f}\\ \left(6\text{kg}\cdot \text{m}/\text{s}+0\text{kg}\cdot \text{m}/\text{s}\right)=\left(2\text{kg}\cdot \text{m}/\text{s}+P_{w,f}\right)\\ P_{w,f}=\left(6\text{kg}\cdot \text{m}/\text{s}-2\text{kg}\cdot \text{m}/\text{s}\right)\\ P_{w,f}=4\text{kg}\cdot \text{m}/\text{s}\end{array}$

Conclusion:

Hence, the momentum of the wooden ball after the collision is $4\text{kg}\cdot \text{m}/\text{s}$ .