Question

A car decreases its speed from 80 km/h to 60 km/h is 5 second. The acceleration of the car is :

• A. -1.11 $m/s^2$
• B. 1.12 $m/s^2$
• C. -1.14 $m/s^2$
• D. 1.11 $m/s^2$

Answer 1

The correct option is A

-1.11 $m/s^2$

Here,

$u=80km/h=80\times \frac{5}{18}=22.22m{s}^{-1}$

$v=60km/h=60\times \frac{5}{18}=16.22m{s}^{-1}$

t = 5s

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

a = $\frac{16.67-22.22}{5}$ $m/s^2$

a = - 1.11 $m/s^2$