Advertisements
Advertisements
प्रश्न
State the condition when the work done by a force is positive. Explain with the help of examples.
उत्तर
If the displacement of the body is in the direction of force, then work done is positive.
Hence, W= F × S
For example: A coolie does work on the load when he raises it up against the force of gravity. The force exerted by coolie (=mg) and displacement, both are in upward direction.
APPEARS IN
संबंधित प्रश्न
A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road.
Who does more work against the force of gravity and why?
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 ______.
What is the work done when the force on the object and the displacement of the object are perpendicular to each other?
Work done by a force is equal to the product of ....... and ....
A man spends 7.4 kJ energy in displacing a body by 74 m in the direction in which he applies force, in 2.5 s. Calculate the power spent (in H.P) by the man.
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes.
How much work each does? Take density of water = 103 kg m-3 and g = 9.8 N kg-1.
State the condition when the work done by the force is positive