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प्रश्न
Mention whether work is done or not in the following activity.
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | |
| 2. | Holding a doll | |
| 3. | Sitting in a bus | |
| 4. | Pushing a wall | |
| 5. | Digging soil |
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उत्तर
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | Work done |
| 2. | Holding a doll | Not done |
| 3. | Sitting in a bus | Not done |
| 4. | Pushing a wall | Not done |
| 5. | Digging soil | Work done |
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संबंधित प्रश्न
Express joule in terms of erg.
1 J = ______ calorie.
If the work done by a force in moving an object through a distance of 20 cm is 24.2 J, what is the magnitude of the force?
Explain by an example that a body may possess energy even when it is not in motion.
Define the term 'work'. Write the formula for the work done on a body when a force acts on the body in the direction of its displacement. Give the meaning of each symbol which occurs in the formula.
An object is dropped from a height H. when is its
(i) P.E. maximum,
(ii) K.E. maximum,
(iii) P.E. = K.E.?
An electric motor drives a machine which lifts a mass of 4 kg through a height of 10 m in 5 s at a constant speed. Assuming g = 10 ms-2, calculate
(i) the amount of work done, (ii) the power of the machine.
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
