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प्रश्न
State the SI unit of work.
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उत्तर
Joule is the SI unit of work. It is denoted by ‘J.
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.
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
In case of negative work, the angle between the force and displacement is :
Name the physical quantity whose SI unit is Nm.
Draw a neat labeled diagram to show the direction of two forces acting on a body to produce rotation in it. Also mark the point about which rotation takes place.
State the conditions of equilibrium for a rigid body.
What do you mean by a kilo joule?
What is the ratio of SI units to CGS units of 'work'?
An object is dropped from a height H. when is its
(i) P.E. maximum,
(ii) K.E. maximum,
(iii) P.E. = K.E.?
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
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 |
A force can cause an object to change its ______.
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.
