Heena Sharma, Shubhankat Vats and, Rashmi Gupta Solutions for Chapter: Force and Laws of Motion, Exercise 5: Challengers*

A body of weight $2 \mathrm{k}\mathrm{g}$ is suspended as shown in figure.

The tension $T$, in the horizontal string in $\left(\mathrm{k}\mathrm{g} \mathrm{w}\mathrm{t}\right)$ is

The pulleys and strings shown in the figure are smooth and of negligible mass.

For the system to remain in equilibrium the angle $\mathrm{\theta }$ should be

A bullet of mass $10 \mathrm{g}$ moving with a velocity of $400 \mathrm{m} {\mathrm{s}}^{-1}$ gets embedded in a freely suspended wooden block of mass $900\mathrm{g}$. What is the velocity acquired by the block?

During a football match the ball shot towards the goal struck the defender’s foot at the speed of $10 \mathrm{m} {\mathrm{s}}^{-1}$ and it bounces back at $20 \mathrm{m} {\mathrm{s}}^{-1}$. If the time of impact was $0.2 \mathrm{s}$ and mass of the ball is $0.5 \mathrm{k}\mathrm{g}$ will then the average force exerted by defender on the ball will be

A mass of $100 \mathrm{g}$ strikes the wall with speed $5 \mathrm{m} {\mathrm{s}}^{-1}$ an on angle as shown in figure, and it rebounds with the same speed. If the contact time is $2\times {10}^{-3}\mathrm{}\mathrm{s}$. Then force applied by the wall is

Two particles $A$ and $B$ of masses $20 \mathrm{g}$ and $30 \mathrm{g}$, respectively are at rest at a certain time. Because of the forces exerted by them on each other, the particles start moving. At a given instant, particle $A$ is found to move towards the East with a velocity of $6 \mathrm{c}\mathrm{m} {\mathrm{s}}^{-1}$. What is the velocity of particle $B$ at this instant?

A car is moving with uniform velocity on a rough horizontal road. Therefore, according to Newton’s first law of motion.

A ship of mass $3\times {10}^7 \mathrm{k}\mathrm{g}$ initially at rest is pulled by a force of $5\times {10}^4 \mathrm{N}$ through a distance of $3 \mathrm{m}$. Assume that the resistance due to water is negligible, the speed of the ship is