Power required by a boy of mass 30 kg to run up a staircase of 40 steps in 10 seconds in (Height of each step is 15 cm) (Take g = 10 m/s2)

To calculate the power required by the boy, we use the formula for power as the rate of doing work against gravity: P = (mgh) / t. First, determine the total vertical height (h) climbed. The boy climbs 40 steps, each with a height of 15 cm (0.15 m). Thus, h = 40 × 0.15 m = 6 m. The mass (m) is given as 30 kg, and the acceleration due to gravity (g) is 10 m/s². The work done (W) or gravitational potential energy gained is W = mgh = 30 kg × 10 m/s² × 6 m = 1800 Joules. Power is then calculated by dividing the work done by the time taken (t = 10 seconds): P = 1800 J / 10 s = 180 Watts. Therefore, the power developed by the boy is 180 Watt.