Question

A bus decreases its speed from 100 km/h to 80 km/h in 5 s. Find the acceleration of the bus.

• A. -1.2 $m/s^2$
• B. -1.6 $m/s^2$
• C. -1.112 $m/s^2$
• D. -1.116 $m/s^2$

Answer 1

The correct option is C

-1.112 $m/s^2$

Initial speed of bus, u = 100 km/h = $100\times \left(\frac{5}{18}\right)$ m/s = 27.78 m/s

Final speed of the bus, v = 80 km/h = $80\times \left(\frac{5}{18}\right)$ m/s = 22.22 m/s

Time taken, t = 5 s

Now, acceleration , a = $\frac{v-u}{t}$ = $\frac{22.22-27.78}{5}$ $m/s^2$ = -1.112 $m/s^2$