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प्रश्न
उत्तर
'Work' is said to be done when the applied force makes the body move i.e., there is a displacement of body.
It is equal to the product of force and the displacement of the point of application of the force in the direction of force.
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संबंधित प्रश्न
State two conditions when no work is done by a force.
State the S.I. unit of work and define it.
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.
How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.
How many joules are there in 1 mega joule?
A machine raises a load of 750 N through a height of 16 m in 5s. calculate:
(i) work done by machine,
(ii) power at which the machine works.
How much energy is gained by a box of mass 20 kg when a man, runs carrying the box with a speed of 3 m/s-1 to catch the bus?
A coolie, with a load of 30 kg on his head, walks on the platform. If he walks a distance of 60 m, what is the work done by him?
Can two agents, doing the same work, have different power?
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
What should be the characteristic of a source of energy?
What is the difference between renewable and non-renewable resources?
An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water. Calculate the work done on the water in one minute.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
