V K Sally and R Goel Solutions for Chapter: Work and Energy, Exercise 10: EXERCISE

 An object of mass $40 \text{kg}$ ($\mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}$) is raised to a height of $8 \text{m}$ above the ground. The gain in potential energy by the object:
 

An object of mass $40 \text{kg}$ ($\mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}$) is raised to a height of $8 \text{m}$ above the ground. If the object falls from its highest position to half way distance, its kinetic energy is:

A nail becomes hot when it is hammered by moving hammer in a plank :

A hammer of mass $1 \text{kg}$ falls freely on a nail from a height of $1 \text{m}$. The kinetic energy of hammer, just before hitting the nail is _____. [$g=10 \mathrm{m} {\mathrm{s}}^{-2}$]

A rocket of mass $3\times {10}^6 \mathrm{kg}$ takes off from a launching pad and acquires a vertical velocity of $1 \mathrm{km} {\mathrm{s}}^{-1}$ at an altitude of $25 \mathrm{km}$ from launching pad. The potential energy of the rocket is: $\left(\mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

A rocket of mass $3\times {10}^6 \mathrm{kg}$ takes off from a launching pad and acquires a vertical velocity of $1 \mathrm{km} {\mathrm{s}}^{-1}$ at an altitude of $25 \mathrm{km}$. The kinetic energy of rocket is: 

In a loudspeaker, the:

Chlorophyll in plants converts light energy into: