Answer:
Step-by-step explanation:
Power = Force * distance/time
Given
mass = 55kg
Force = 55 * 10 = 550N
Let the distance covered be 8m
time taken = 5secs
Required
Amount of Power used
Power = 550 * 8/5
Power = 110 * 8
Power = 880 Watts
2) The way he can reduce the amount of power expended is to reduce the amount of stairs or the distance covered in a specified period of time.