Final answer:
To find the power, multiply the weight of the student (500N) by the height climbed (15m) to find the work done (7500 J), then divide by the time taken (20s) to get the power output, which is 375 Watts.
Step-by-step explanation:
Calculating Power in Climbing Stairs
To calculate the power exerted by the student climbing the stairs, we use the formula:
Power (P) = Work done (W) / Time (t)
Work done, which is also the gravitational potential energy gained, can be calculated by:
Work (W) = Weight (Force due to gravity) x Height (h)
In this case, the student weighs 500N and climbs a height of 15 meters:
W = 500N x 15m = 7500 J (Joules)
The time taken to climb is 20 seconds, so we calculate power as:
P = 7500 J / 20 s = 375 W (Watts)
Therefore, the power exerted by the student is 375 Watts.