Question

If a bus travelling at $20m/s$ is subject to a steady deceleration of $5m/s^2$, how long will it take to come rest?

• A. 400 s
• B. 0.4 s
• C. 40 s
• D. 4 s

Answer 1

The correct option is D 4 s

Using first equation of motion

$v=u+at$, we have

$0=20+(-5)t$

$\Rightarrow 5t=20$

$\Rightarrow t=4s$