Question

1. a ball is kicked forward. describe how newtons first and third laws both apply in this situation.

part c - calculations

1. a sprinter runs 150 m in 15 seconds. what is their speed?
2. a skateboarder moves 80 m north in 20 seconds. what is their velocity?

Explanation:

Step1: Recall speed formula

Speed $v=\frac{d}{t}$, where $d$ is distance and $t$ is time.

Step2: Solve for sprinter's speed

Given $d = 150$ m and $t=15$ s, then $v=\frac{150}{15}=10$ m/s.

Step3: Recall velocity formula

Velocity $\vec{v}=\frac{\vec{d}}{t}$, where $\vec{d}$ is displacement and $t$ is time.

Step4: Solve for skate - boarder's velocity

Given $\vec{d}=80$ m north and $t = 20$ s, then $\vec{v}=\frac{80}{20}=4$ m/s north.

Answer:

1. 10 m/s
2. 4 m/s north