Question

In an experiment to measure his power, a student records the time taken by him in running up a flight of steps on a staircase. Use the following data to calculate the power of the student :

Number of steps = 28

Height of each step = 20 cm

Time taken = 5.4 s

Mass of student = 55 kg

Acceleration = 9.8 $m{s}^{-2}$

due to gravity

Answer 1

Total height of reached by the student = 28 ×​ 20 / 100 = 5.6 m
work done by the student = potential energy that gets stored i him = m×g×h = 55 ×​ 9.8 ×​ 5.6
now,
power = work done / time taken
power = 55 ×​ 9.8 ×​ 5.6 / 5.4 = 558.96 W
= 559 w