A man 'p' 80kg runs upstairs in 12 seconds.another man 'q' 60kg runs the same stairs in 11seconds.what is the ratio of power of p to q?

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Answer 1 · 2018-07-02T12:37:32

#11/9#

If #\theta# is the angle of inclination & length of stairs be #L# which a person covers in time #t# then

Power #=\text{force}\times\text{velocity}#

#P=mg\sin\theta\times (L/t)#

#P\prop(m/t)#

Hence, the ratio of powers of person p & person q

#\frac{P_p}{P_q}=\frac{(m/t)_p}{(m/t)_q}#

#=(m_p/m_q)(t_q/t_p)#

#=(80/60)(11/12)#

#=11/9#