Question

A boy of mass 40 kg climbs 20 steps of a staircase, each measuring 20 cm high in 30 s. Calculate the
power developed by the boy. Take g=10 m/s2​

Answer 1

Answer:

53.33

Explanation:

Vertical height climbed = Height of step × No.of steps=20cm×20=400 cm=4 m

Mass of the girl =40 kg

Since, work done is equal to gain in potential energy, therefore we have =40×10×4=1600 J

Hence power developed by the girl:

P =

t

W

=

30

1600

=53.33 W

Answer 2

Answer:

Explanation:

Vertical height climbed = Height of step × No.of steps=20cm×20=400 cm=4 m

Mass of the girl =40 kg

Since, work done is equal to gain in potential energy, therefore we have =40×10×4=1600 J

Hence power developed by the girl:

P =

t W = 30

1600

=53.33 W