Question

know how to do momentum problems: equation: p = m x v show work and dont forget units!

1. a 15-kg car has a speed of 35 m/s. what is its momentum?
2. if a 35-kg truck wants to have the same momentum as the car in problem 16, what should its velocity be?

Explanation:

Step1: Calculate car's momentum

Use $p = m \times v$, substitute $m=15\ \text{kg}$, $v=35\ \text{m/s}$
$p = 15\ \text{kg} \times 35\ \text{m/s} = 525\ \text{kg·m/s}$

Step2: Solve for truck's velocity

Rearrange $p = m \times v$ to $v = \frac{p}{m}$, substitute $p=525\ \text{kg·m/s}$, $m=35\ \text{kg}$
$v = \frac{525\ \text{kg·m/s}}{35\ \text{kg}} = 15\ \text{m/s}$

Answer:

1. $525\ \text{kg·m/s}$
2. $15\ \text{m/s}$