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प्रश्न
Can every force produce work?
उत्तर
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संबंधित प्रश्न
Define work.
In which of the following cases is work being done:
- A boy pushing a heavy rock
- A boy climbing up the stairs
- A coolie standing with a box on his head
- A girl moving on the road.
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.
A boy weighing 25 kgf climbs up from the first floor at height 3 m above the ground to the third floor at height 9m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg -1)
State two disadvantages of producing hydroelectricity.
Is work a scalar or a vector quantity?
What is the work done against gravity when a body is moved horizontally along a frictionless surface?
Explain by an example that a body may possess energy even when it is not in motion.
When do we say that work is done? Write the formula for the work done by a body in moving up against gravity. Give the meaning of each symbol which occurs in it.
When you move upstairs, do you perform some work?
Complete the following sentences:
The SI unit of work is ....... and of power is .......
Define the term work. Name the CGS and SI unit of work.
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
Fill in the boxe to show the corresponding energy transformation.
A force is applied on a body of mass 20 kg moving with a velocity of 40 ms−1. The body attains a velocity of 50 ms−1 in 2 seconds. Calculate the work done by the body.
A body of mass 0.5 kg travels on straight line path with velocity v = (3x2 + 4) m/s. The net work done by the force during its displacement from x = 0 tox = 2 m is ______.
