MCQ
A $ 60 kg$ man runs up a staircase in $ 12$ seconds while a $ 50 kg$ man runs up the same staircase in $11$ , seconds, the ratio of the rate of doing their work is
- A$6:5$
- B$12;11$
- ✓$11:10$
- D$10:11$
✓
Answer
Correct option: C.
$11:10$
c
(c)$P = \frac{{mgh}}{t}$ $⇒$ $\frac{{{P_1}}}{{{P_2}}} = \frac{{{m_1}}}{{{m_2}}} \times \frac{{{t_2}}}{{{t_1}}}$ (As $h$ = constant)
$\frac{{{P_1}}}{{{P_2}}} = \frac{{60}}{{50}} \times \frac{{11}}{{12}} = \frac{{11}}{{10}}$
(c)$P = \frac{{mgh}}{t}$ $⇒$ $\frac{{{P_1}}}{{{P_2}}} = \frac{{{m_1}}}{{{m_2}}} \times \frac{{{t_2}}}{{{t_1}}}$ (As $h$ = constant)
$\frac{{{P_1}}}{{{P_2}}} = \frac{{60}}{{50}} \times \frac{{11}}{{12}} = \frac{{11}}{{10}}$
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