Question

A car, initially traveling at 79.8 mi/h, slows to rest in 9.5 s. What is the car's acceleration?

Answer 1

Given:

The initial velocity of the car, u=79.8 mi/h

The final velocity of the car, v=-0 m/s

The time it takes for the car to come to rest, t=9.5 s

To find:

The acceleration of the car.

Step-by-step explanation:

The initial velocity of the car in m/s is u=35.67 m/s

From the equation of motion,

`v=u+at`

On substituting the known values,

`\begin{gathered} 0=35.67+a*9.5 \\ \Rightarrow a=(-35.67)/(9.5) \\ =-3.75\text{ m/s}^2 \end{gathered}`

Final answer:

The acceleration of the car is -3.75 m/s²