Question

A bus starts from the stop and takes $50$ seconds to attain the speed of $10m/s$. If the mass of the bus along with the passengers is $10000kg$, the force applied (in N) by the engine of the bus to attain the speed of $10m/s$ is ___ N.

• A. $1000$ N
• B. $2000$ N
• C. $4000$ N
• D. None of these

Answer 1

The correct option is B

$2000$ N

Given, Initial velocity $u=0$, final velocity $v=10$ m/s, time $t=50$ second, Mass $m=10000$ kg,

We know that, Force $F=ma$ [Newton's Second Law]

$\Rightarrow F=m\frac{v-u}{t}$ [$\because v=u+at$ $\Rightarrow a=\frac{v-u}{t}$]
Therefore, $F=10000\frac{10-0}{50}$
$\Rightarrow 10000\times \frac{1}{5}$ $m{s}^{-2}$

$F=2000$ $kgm{s}^{-2}$ or, $2000$ N

Thus, required force $=2000$ N