A car slows from 22m/s to 3.0m/a at a constant rate of 2.1m/s. How many seconds are required before the car is traveling at 3.0m/s?

t = 9.05 s

Explanation:

Given,

The initial velocity of the car, u = 22 m/s

The final velocity of the car, v = 3.0 m/s

The rate of change of speed of the car is 2.1 m/s,

∴ the acceleration, a = - 2.1 m/s²

The acceleration and velocity is given by the relation

a = (v - u) / t m/s²

Therefore,

t = (v-u) / a s

Substituting the values in the above equation

t = (3.0 - 22) / (-2.1)

= 9.05 s

Hence, the time required before the car is traveling at 3.0m/s is t = 9.05 s