H C Verma Solutions for Chapter: Work and Energy, Exercise 3: OBJECTIVE II

The total work done on a particle is equal to the change in its kinetic energy

Consider two observers moving with respect to each other at a speed$v$ along a straight line. They observe a block of mass $m$ moving a distance $l$ on a rough surface. Which among the following quantities will be the same as observed by the two observers?

You lift a suitcase from the floor and keep it on a table. The work done by you on the suitcase does not depend on

No work is done by a force on an object if

A particle of mass $m$ is attached to a light string of length $l,$ the other end of which is fixed. Initially, the string is kept horizontal and the particle is given an upward velocity $v$. The particle is just able to complete a circle. Then,

The kinetic energy of a particle continuously increases with time. Then

One end of a light spring of spring constant $k$, is fixed to a wall and the other end is tied to a block placed on a smooth horizontal surface. In a displacement, the work done by the spring is $\frac{1}{2}k{x}^2$. The possible cases are

A block of mass $M$ is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force $F$. The kinetic energy of the block increases by $20 \mathrm{J}$ in $1 \mathrm{s}$.