Question

You are driving at 50 m/s when you hit your brakes for 5 seconds. Your new speed is 30 m/s. What was your acceleration?A. 4 m/s2B. 16 m/s2C. -16 m/s2D. – 4 m/s2

Answer 1

D. - 4 m/s

Explanation:

Given:

Final velocity (v) = 30 m/s

Initial velocity (u) = 50 m/s

Time (t) = 5 s

We can determine the acceleration by the following formula:

`\begin{gathered} a=(\Delta v)/(\Delta t)=(v-u)/(t) \\ \\ \text{ we replacing:} \\ \\ a=(30-50)/(5)=(-20)/(5) \\ \\ a=-4\text{ m/s}^2 \end{gathered}`

The acceleration is equal to - 4 m/s², therefore, the correct answer is D.