Question

A body initially moving with a velocity of $4{\text{ms}}^{–1}$, attains a velocity of $20{\text{ms}}^{–1}$ in $4s$ . The acceleration of the body is:
(Assume constant acceleration)

• A. $1{\text{ms}}^{-2}$
• B. $3{\text{ms}}^{-2}$
• C. $2{\text{ms}}^{-2}$
• D. $4{\text{ms}}^{-2}$

Answer 1

The correct option is D $4{\text{ms}}^{-2}$

Given, $u=4{\text{ms}}^{-1},v=20{\text{ms}}^{-1},t=4\text{sec}$
$\because v=u+at$ (from first equation of motion)
$\Rightarrow a=\frac{v-u}{t}=\frac{20-4}{4}=\frac{16}{4}=4{\text{ms}}^{-2}$