Question

A car, moving at 60 mph, comes to rest in 5s. What was the average deceleration of that car?

Answer 1

1/300 mile/`s^2` = 176'`s^2`

Explanation:

Use
Final velocity = initial velocity + acceleration X time.

Average deceleration is the negative of uniform deceleration in the formula.

Maintain parity in time unit..
60 m/h= 60/3600 mile/s=1/60 mile/s

So, `0 = 1/60 +5 a`.
Acceleration a =`-1/300` mile/`s^2=-(5280/300)`'/`s^2=-`176'/`s^2`. .
Deceleration is 176'/`s^2`..