A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the heig

1.	A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the height of each step is 15 cm, find his power. (Take g = 10 ms-2 )
Answer» Given Mass of Body (m) = 50 Kg, Time (t) = 9s, Height of each step = 15 cm, Acceleration due to gravity (g) = 10 m/s² . Now Weight = mg = 50×10 = 500N Height of staircase = 45 x \(\frac{15}{100}\) = 6.75 m (∵ 1m = 100 cm ) Power = \(\frac{Work}{Time}\) = \(\frac{mgh}{t}\) ⇒ Power = \(\frac{500\times6.75}{9}\) = \(\frac{3375}{9}\) Power = 375 Watt

A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the height of each step is 15 cm, find his power. (Take g = 10 ms-2 )

Answer»

Given

Mass of Body (m) = 50 Kg,

Time (t) = 9s,

Height of each step = 15 cm,

Acceleration due to gravity (g) = 10 m/s² .

Now

Weight = mg = 50×10 = 500N

Height of staircase = 45 x \(\frac{15}{100}\) = 6.75 m (∵ 1m = 100 cm )

Power = \(\frac{Work}{Time}\) = \(\frac{mgh}{t}\)

⇒ Power = \(\frac{500\times6.75}{9}\) = \(\frac{3375}{9}\)

Power = 375 Watt