Question

A vehicle of $100kg$ is moving with a velocity of $5m/s$. To stop it in $1/10sec$, required force in opposite direction is ___________________$N$

• A. $50$
• B. $500$
• C. $5000$
• D. $1000$

Answer 1

The correct option is C $5000$

Consider the problem

Given,

The mass of the vehicle $m=100kg$

The initial velocity $u=5m/s.$

The time required to stop the vehicle $t=\frac{1}{10}\sec$ i.e $0.1second.$

The final velocity of the vehicle $v=0m/s.$

As per Newton's second law of motion, we know that force is equal to rate of change of momentum.

$F=\frac{dp}{dt}$

Here $F$ and $p$ stands for force and momentum

$\begin{array}{c}=m\frac{v-u}{t}\\ =100\frac{[0-5]}{0.1}N\\ =-5000N\end{array}$

The Negative sign indicates the force is in opposite direction

Therefore, $F=5000N$

Hence, Option $C$ is the correct answer.