Jatinder Singh Solutions for Chapter: Work, Energy and Power, Exercise 2: TEST YOURSELF

A motor rated at $25 \mathrm{hp}$ is used to pump water to the top of a skyscraper $100 \mathrm{m}$high. How long will it take to pump $80 {\mathrm{m}}^3$of water to the top. $(1 \mathrm{hp} = 750 \mathrm{watts})$

Calculate the power developed by a man who is able to run up a flight of $30$ steps in $15 \mathrm{s}$. Height of each step is $20 \mathrm{cm}$and mass of man is $60 \mathrm{kg}$. Use $g=10 {\mathrm{ms}}^{-2}$.

A lighter and a heavier body have equal kinetic energy, which will have more momentum$?$

Explain the energy changes in an oscillating simple pendulum.

Give the relation between $1 \mathrm{kWh}$and $\mathrm{joule}.$

What type of energy is stored in the spring of a watch?

State the energy changes in an oscillating pendulum.

Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.