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प्रश्न
Name the CGS unit of work.
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उत्तर
The CGS unit of work is ‘erg’.
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संबंधित प्रश्न
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.
Explain by an example that a body may possess energy even when it is not in motion.
In case of negative work, the angle between the force and displacement is :
State the conditions of equilibrium for a rigid body.
In the following case write yes, if the work is being done and no if no work is being done.
A boy climbing up a staircase.
A block of mass 30 kg is pulled up a slope, as shown in diagram with a constant speed, by applying a force of 200 N parallel to slope.
A and B are initial and final positions of block.
(i) Calculate the work done by force in moving the block from A to B.
(ii) Calculate P.E. gained by block. [g=10ms-2]
A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s2, find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A donkey is carrying a load on its back.
