A boy weighing $40 k g f$ climbs up a stair of $30$ steps each $20 c m$ high in $4 m i n u t e s$ and a girl weighing $30 k g f$ does the same in $3 m i n u t e s$ . Compare
(i) The work done by them.

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Solution

Step 1: Given data
The given in the above question are as bellow,
Weight of a Boy is $m_{1} = 40 K g f$
Time taken by the boy to climb upstairs is $4 m i n u t e s$
Weight of a Girl is $m_{2} = 30 K g f$
Time taken by the girl to climb upstairs The height $3 m i n u t e s$
Height of each step is $20 c m$
Step 2: The work done by them:
Now the steps climbed by both girl $h_{g}$ and boy $h_{b}$ ,
$= 30 \times 20 = 600 c m = 6 m$
Comparing work done by both boys and girls is,
$\frac{W o r k d o n e b y b o y}{W o r k d o n e b y g i r l} = \frac{m_{1} g h_{b}}{m_{2} g h_{g}} = \frac{m_{1} h_{b}}{m_{2} h_{g}} = \frac{40 \times 6}{30 \times 6} = \frac{40}{30} = \frac{4}{3}$
Hence the work done by both of them is $\frac{4}{3} .$

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A boy weighing 40kgf climbs up a stair of 30 steps each 20cm high in 4minutes and a girl weighing 30kgf does the same in 3minutes. Compare(i) The work done by them.

A boy weighing $40 k g f$ climbs up a stair of $30$ steps each $20 c m$ high in $4 m i n u t e s$ and a girl weighing $30 k g f$ does the same in $3 m i n u t e s$ . Compare
(i) The work done by them.