Advertisements
Advertisements
प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Food grains are getting dried in the sun.
उत्तर
The grains of corn are drying in the heat of the sun; here, also, no work is being done because the grains are stable in their place. There is no displacement in them.
APPEARS IN
संबंधित प्रश्न
Work done by a boy depends on the time in which he does work.
The moon is revolving around the earth in a circular path. How much work is done by the moon?
A man lifts a mass of 20 kg to a height of 2.5 m. Assuming that the force of gravity on 1 kg mass is 10 N, find the work done by the man.
A body, when acted upon by a force of 10 kgf, moves to a distance 0.5 m in the direction of force. Find the work done by the force. Take 1 kgf = 10 N.
Name the forms of energy which a wound-up watch spring possesses.
The power of a motor is 40 kW. At what speed can the motor raise a load of 20,000 N?
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
When do we say that work is done? Write the formula for the work done by a body in moving up against gravity. Give the meaning of each symbol which occurs in it.
Why is the work done on an object moving with uniform circular motion zero?
Write an expression for work done by a force depends?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
Define energy and state the unit of energy and the law of conservation of energy.
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).
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
