Question

A bus starting from rest moves with a uniform acceleration of $0.1m{s}^{-2}$ for $2minutes$. Find
(a) the speed acquired, (b) the distance travelled.

• A. $12m{s}^{-1}$ , $700m$
• B. $12m{s}^{-1}$ , $720m$
• C. $10m{s}^{-1}$ , $700m$
• D. $10m{s}^{-1}$ , $720m$

Answer 1

The correct option is B $12m{s}^{-1}$ , $720m$

Given,
initial speed of the bus, $u=0$,
acceleration, $a=0.1m{s}^{-2}$
and time taken, $t=2minutes=2\times 60=120s$

Let $v$ be the final velocity and $s$ be the distance covered.
(a) From the first equation of motion,$v=u+at$,
$v=0+(0.1\times 120)$
$\Rightarrow$ $v=12m{s}^{-1}$

(b) According to the third equation of motion, $v^2-u^2=2as$
$(12{)}^2-(0{)}^2=2\times 0.1\times s$
$\Rightarrow s=720m$
Speed acquired by the bus is $12m{s}^{-1}$ and the distance travelled is $720m$.