Sunil Batra Solutions for Chapter: Work and Energy, Exercise 5: Summative Assessment

What type of energy conversion takes place in a thermal power plant ?

A man throws a ball of $500\mathrm{g}$ in vertically upward direction with a speed of $10\mathrm{m}/\mathrm{s}$. Calculate the amount of work done by the force of gravity in $1$ second. (Take$\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2$)

Find the energy possessed by an object of mass $10 \mathrm{kg}$ when it is at a height of $6 \mathrm{m}$ above the ground. (Given $\mathrm{g}=9.8 \mathrm{m}/{\mathrm{s}}^2$).

An object of mass $12 \mathrm{kg}$ is at a certain height above the ground. If the potential energy of the object is $4800 \mathrm{J}$, find the height at which the object is with respect to the ground. (Given $\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2$)

Two girls each of weight $400 \mathrm{N}$ climb up a rope through a height of $8 \mathrm{m}$. We name one girl A and the other B. Girl A takes $20\mathrm{s}$ while $\mathrm{B}$ takes $50 \mathrm{s}$ to accomplish this task. What is the power applied by each girl?

A boy of mass $50 \mathrm{kg}$ runs to a staircase of $45$ steps in $9 \mathrm{s}$. If the height of each step is $15 \mathrm{cm}$, find his power. (Take $\mathrm{g}= 10 \mathrm{m}/{\mathrm{s}}^2$)

An electric bulb of $60\mathrm{W}$ is used for $6\mathrm{h}$ per day. Calculate the units of energy consumed in one day by the bulb.

A ball is dropped from a height $\mathrm{h}$. The velocity of the ball when it reaches the ground is $10 \mathrm{m}/\mathrm{s}$. Find $\mathrm{h}$.(Take $\mathrm{g}=10\mathrm{m}/{\mathrm{s}}^2$).