Question

2. a body weighing 40kgf ,climbs up a stare of 30 steps each of 20cm heigh in 4 min and a girl weighing 30kgf does the same in 3min. Compare thier workdone by them and the power devloped by them.

Answer 1

Dear student
$$\begin{gathered} Heighttobeclimbed=30\times 20cm=600cm=6m \\ workdone=Increaseinpotentialenergy \\ 1)W_1=m_{1}gh=40\times 10\times 6=2400J \\ workdoneintheothercase \\ 2)W_2=m_{2}gh=30\times 10\times 6=1800J \\ Powerisrateofworkdoneso \\ 1)P_1=\frac{W_1}{t_1}=\frac{2400}{4\times 60}=10J/s \\ Powerinthesecondcaseis \\ {P}_2=\frac{W_2}{t_2}=\frac{1800}{3\times 60}=10J/s \\ Regards \end{gathered}$$