Embibe Experts Solutions for Chapter: Work, Energy and Power, Exercise 1: Exercise 1

The potential energy of particle in a force field is $U=\frac{A}{r^2}-\frac{B}{r},$ where $A$ and $B$ are positive constants and $r$ is the distance of particle from the centre of the field. For stable equilibrium, the distance of the particle is:

A force of $\left(5+3 x\right)$ $\mathrm{N}$ acting on a body of mass $20 \mathrm{kg}$ along the $x$-axis displaces it from $x=2 \mathrm{m}$ to $x=6 \mathrm{m}$. The work done by the force is

Before a rubber ball bounces off from the floor, the ball is in contact with the floor for a fraction of second. Which of the following statements is correct?

A particle describe a horizontal circle of radius $0.5 \mathrm{m}$ with uniform speed. The centripetal force acting is $10 \mathrm{N}$. The work done in describing a semicircle is

A boy pushes a toy box $2.0 \mathrm{m}$ along the floor by means of a force of $10 \mathrm{N}$ directed downward at an angle of $60°$ to the horizontal. The work done by the boy is

A motor of $100 \mathrm{H}.\mathrm{P}.$ moves a load with a uniform speed of $72 \mathrm{km} {\mathrm{hr}}^{-1}$. The forward thrust applied by the engine on the car is

A body accelerates uniformly from rest to a velocity of $1 \mathrm{m} {\mathrm{s}}^{-1}$ in $15$ seconds. The kinetic energy of the body will be $\frac{2}{9} \mathrm{J}$  when $\text{'}t\text{'}$ is equal to [Take mass of body as $1 \mathrm{kg}$

Two bodies $A$ and $B$ having masses in the ratio of $3: 1$ possess the same kinetic energy. The ratio of linear momentum of $B$ to $A$ is