A boy of mass 50Kg runs up a staircase of 45 staps in 9 s. if the height of each step is 15cm, find his power.Take g=10ms-2
Answers
here m= 50 kg
total steps = 45
t= 9 secs
total height = total displacement= 15/100×45 = 27/4 m
work done = Fs
work done = mgs
work done= 50×10×27/4 = 3375 joules
Power = work done/ time
Power= 3375/ 9 = 375 watt
Answer:
The power is 375 W.
Explanation:
Given,
A boy of mass (m) = 50 kg
No. of steps = n = 45
Time taken (t) = 9 s
Height of each step = 15 cm = 15 / 100 m
To find: find his power
Solution:
Concept involved: Power is the rate of doing work.
Total height of staircase = No. of steps * height of each step
or, Total height of staircase = 45 * 15 / 100 = 6.75 m
Work done would be equal to the Potential Energy possessed by the body.
i.e W = mgh
here, m = 50 kg , g = 10 m/s^2, h = 6.75 m
Substituting the values,
W = 50*10*6.75
And, Power = work done / time
or, P = W / t
or, P = 50*10*6.75 / 9
or, P = 375 W
Therefore, The power is 375 W.