Sunil Batra Solutions for Chapter: Work and Energy, Exercise 4: HOTS Higher Order Thinking Skill & Brain Twisting

Find the ratio of powers of the following two persons?

(a) Person $\mathrm{A}$ does a work of $100 \mathrm{J}$ in $5$ seconds.

(b) Person $\mathrm{B}$ does a work of $200 \mathrm{J}$ in $6$ seconds.

It is given that ${\mathrm{W}}_1>{\mathrm{W}}_2$ where ${\mathrm{W}}_1$ is the work done by one force and ${\mathrm{W}}_2$ is the work done by another force. Can we say confidently that ${\mathrm{P}}_1>{\mathrm{P}}_2$, where ${\mathrm{P}}_1$ is the power delivered by force ${\mathrm{F}}_1$ and ${\mathrm{P}}_2$ is the power delivered by force ${\mathrm{F}}_2$?

Two persons $\mathrm{A}$ and $\mathrm{B}$ do same amount of work. The person $\mathrm{A}$ does that work in $t_{\mathrm{A}}$ seconds and person $\mathrm{B}$ in $t_{\mathit{B}}$ seconds. Find the ratio of power delivered by them.

Our hands become warm when rubbed against each other. Explain.

Two bodies $\mathrm{A}$ and $\mathrm{B}$ have equal kinetic energies. If mass of $\mathrm{A}$ is greater than mass of $\mathrm{B}$, then which body has more linear momentum?

In the given figure, the block moves horizontally towards right. Which force(s) do work?

Work done by the force for a horizontal displacement of $3 \mathrm{m}$ in the given figure is _____.

A skater of mass $50 \mathrm{kg}$ moves down from $\mathrm{A}$ to $\mathrm{B}$. The frictional forces are absent. What is the kinetic energy at $\mathrm{B}$? (take $\mathrm{g}=10 {\mathrm{ms}}^{-2}$).