A boy whose mass is 40kg runs up a flight of 30 steps each 150mm high in 6seconds. Find the average power developed (take g as 10m/s^2).
See previous post.
300W
750
To find the average power developed by the boy while running up the flight of steps, we need to use the formula:
Average Power = Work / Time
Now let's break down the problem step by step.
1. First, we need to find the work done by the boy. Work is defined as the force applied to an object multiplied by the displacement in the direction of the force. In this case, the force is the weight of the boy and the displacement is the height of the steps.
Work = Force * Height
The weight of the boy can be determined using the formula:
Weight = Mass * Acceleration due to gravity
Weight = 40 kg * 10 m/s^2
Weight = 400 N
Now, substituting the values into the work formula:
Work = 400 N * (30 steps * 150 mm)
Work = 400 N * (30 * 0.15 m)
Work = 400 N * 4.5 m
Work = 1800 Joules
2. Next, we need to calculate the time taken by the boy. Given that the time taken is 6 seconds.
Time = 6 seconds
3. Finally, we can now calculate the average power by dividing the work done by the time taken.
Average Power = Work / Time
Average Power = 1800 J / 6 s
Average Power = 300 Watts
Therefore, the average power developed by the boy while running up the flight of steps is 300 Watts.