Advertisements
Advertisements
प्रश्न
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
Advertisements
उत्तर
Given, mass = 50kg
Total height traveled = 40 x 20 cm = 800 cm = 8 m
g = 10ms-2
time taken = 20s
work done = mgh = 50 x 10 x 8 = 4000 J
power = `"work done"/"time taken" = 4000/20 = 200 "watt"`
APPEARS IN
संबंधित प्रश्न
An electron emitter must have _____________ work function and ___________ melting point.
What are the two kinds of mechanical energy?
When is work said to be done by a force?
Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
Does the earth move around the sun with a uniform velocity?
A body does 20 J of work in 10 s. What is its power?
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.
