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संबंधित प्रश्न
A boy weighing 40 kgf climbs up a stair of 30 steps each 20 cm high in 4 minutes and a girl weighing 30 kgf does the same in 3 minutes. Compare:
- The work done by them.
- The power developed by them.
A body is moved in a direction opposite to the direction of force acting on it. State whether the work is done by the force or work is done against the force
Give an example when work done by the force of gravity acting on a body is zero even though the body gets displaced from its initial position.
Name the quality which is measured in kWh.
kWh is the unit of ______.
Is it possible that no transfer of energy may take place even when a force is applied to a body?
A body is provided at a point. A force of 20 N is applied at a distance of 40 cm from the pivot. Find the moment of force about the pivot.
Name the force needed for circular motion. What is the direction of the force?
A pump is used to lift 600 kg of water from a depth of 75 m in 10s. Calculate:
- The work done by the pump,
- the power at which the pump works, and
- The power rating of the pump if its efficiency is 40%. (Take g = 10m s-2).
`["Hint" : "Efficiency" = "useful power"/"power input"]`
Derive a relation between the S.I. and C.G.S. unit of force.
