Advertisements
Advertisements
प्रश्न
What is power?
Advertisements
उत्तर
Power is the rate of doing work or the rate of transfer of energy. If W is the amount of work done in time t, then power is given by the expression,
The rate of doing work or energy conversion rate is called power.
Power = `"Work" /"time"`
or P = `W/t`
Where, P = Power
w = Work
t = Time
APPEARS IN
संबंधित प्रश्न
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
Calculate the work done by the brakes of a car of mass 1000 kg when its speed is reduced from 20 m/s to 10 m/s?
How much is the mass of a man if he has to do 2500 joules of work in climbing a tree 5 m tall? (g = 10 m s−2)
A trolley is pushed along a road with a force of 400 N through a distance of 60 m in 1 minute. Calculate the power developed.
Define power. Give the SI unit of power.
A boy weighing 40 kg carries a box weighing 20 kg to the top of a building 15 m high in 25 seconds. Calculate the power. (g = 10 m/s2)
In an experiment to measure his power, a student records the time taken by him in running up a flight of steps on a staircase. Use the following data to calculate the power of the student :
Number of steps = 28
Height of each step = 20 cm
Time taken = 5.4 s
Mass of student = 55 kg
Acceleration = 9.8 m s−2
due to gravity
In loading a truck, a man lifts boxes of 100 N each through a height of 1.5 m.
How much work does he do in lifting one box?
In loading a truck, a man lifts boxes of 100 N each through a height of 1.5 m.
How much energy is transferred when one box is lifted?
In loading a truck, a man lifts boxes of 100 N each through a height of 1.5 m.
If the man lifts 4 boxes per minute, at what power is he working?
(g = 10 m s−2)
