Question

A bus decreases its speed from 100km/h ti 80km/h in 5s

Answer 1

Given :

The initial velocity of the bus = 100 km/h

$100 \times \frac{5}{18} = 27.77$

m/s

The final velocity of the bus = 80 km/h

$80 \times \frac{5}{18} = 22.22$

m/s

Time taken = 5 sec

To Find : The acceleration produced by the body.

Solution :

We know that the formula of acceleration produced by a body is given by :

$\frac{ v-u}{t} = \\ \\ \frac{22.22 - 27.77}{5} = \\ \\ \frac{ - 5.55}{5} \\ \\ = - 1.11 \: m {s}^{ - 2}$

As the acceleration produced is negative in sign it means it is retardation.