Question

The velocity of a car increases from $20m{s}^{-1}$ to $40m{s}^{-1}$ in $5s$. Calculate the acceleration.

• A. 4

Answer 1

The correct option is A 4
Given:
Initial velocity, $u=20\text{m}{s}^{-1}$
Final velocity, $v=40\text{m}{s}^{-1}$
Time taken, $t=5\text{s}$
Applying first equation of motion,
$\text{v}=u+at$
$\text{a}=\frac{v-u}{t}$
$\text{a}=\frac{40-20}{5}$$\text{m}{s}^{-2}$
$\text{a}=4\text{m}{s}^{-2}$