Question

The speed of a car is decreased uniformly from 30 meters per second to 10 meters per second in 4 seconds. The magnitude of the car's acceleration in m/s^2 is

Answer 1

v=u+at

Acceleration

$a=\frac{v-u}{t}$

$a=\frac{10-30}{4}=\frac{-20}{4}=-5m/sec^2$

Deaccleration