Question

What is the acceleration of a van that starts from rest and attains a velocity of $20m{s}^{-1}$ in $25$ seconds?

• A. $2m{s}^{-2}$
• B. $0.8m{s}^{-2}$
• C. $8m{s}^{-2}$
• D. $5m{s}^{-2}$

Answer 1

The correct option is B

$0.8m{s}^{-2}$

Given:
final velocity, $v=20m{s}^{-1}$,
initial velocity, $u=0$,
time taken, $t=25s$
From first equation of motion: $a=\frac{v-u}{t}$
$\Rightarrow a=\frac{20}{25}$ $m{s}^{-2}$
$\Rightarrow 0.8m{s}^{-2}$