A man of mass 50kg ascends a flight of stairs 5m high in ...
A man of mass 50kg ascends a flight of stairs 5m high in 5 seconds. If acceleration due to gravity is 10ms-2, the power expended is?
100W
200W
250W
400W
500W
Correct answer is E
Power = force x distancetime
= 50×10×55= 500W