Question

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

• 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, $u=0m{s}^{-1}$

Time taken, $t=25s$

From first equation of motion: $a=\frac{v-u}{t}$

$\Rightarrow a=\frac{20}{25}$ $m{s}^{-2}$

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