Embibe Experts Solutions for Chapter: Laws of Motion, Exercise 3: Level 3

A particle having a mass $0.5 \mathrm{kg}$ is projected under gravity with a speed of $98 \mathrm{m} {\sec }^{-1}$ at an angle of $60°$.  The magnitude of the change in momentum (in $\mathrm{N} \sec$) of the particle after $10 \mathrm{seconds}$ is $\left[g=9.8 \mathrm{m} {\mathrm{s}}^{-2}\right]$

A cricket ball of mass $0.5 \mathrm{kg}$ strikes a cricket bat normally with a velocity of $20 \mathrm{m} {\mathrm{s}}^{-1}$  and rebounds with a velocity of $10 \mathrm{m} {\mathrm{s}}^{-1}$. The impulse of the force exerted by the ball on the bat is

Two blocks $A$ and $B$ are placed one over the other on a smooth horizontal surface. The maximum horizontal force that can be applied on lower block $A$, so that $A$ and $B$ move without separation is $49 \mathrm{N}$. The coefficient of friction between $A$ and $B$ is

A cylinder rests in a supporting carriage as shown. The side $AB$ of carriage makes an angle $30°$ with the horizontal and side $BC$ is vertical. The carriage lies on a fixed horizontal surface and is being pulled towards left with an horizontal acceleration $a$. The magnitude of normal reactions exerted by sides $AB$ and $BC$ of carriage on the cylinder be $N_{AB}$ and $N_{BC}$, respectively. Neglect friction everywhere. Then as the magnitude of acceleration $a$ of the carriage is increased, pick up the correct statement.

A weightless thread can bear tension upto $3.7 \mathrm{kg} \mathrm{wt}$. A stone of mass $500 \mathrm{g}$ is tied to it and revolved in a circular path of radius $4 \mathrm{m}$ in a vertical plane. If $g=10 \mathrm{m} {\mathrm{s}}^{-2}$, then the maximum angular velocity of the stone will be

In a tug of war, each of the two teams apply $1000 \mathrm{N}$ force at the ends of a rope which is found to be in equilibrium. The tension in the rope is,

What can be concluded when a $60 \text{kg}$ man standing on a spring scale in a lift, at some instant finds that the scale reading has changed from $60 \text{kg}$ to $50 \text{kg}$ for a while and then comes again to $60 \text{kg}$ mark?

A block of mass $1 \mathrm{kg}$ lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is $0.6$. If the acceleration of the truck is $5\mathrm{m}{\mathrm{s}}^{-2}$, find the frictional force acting on the block.