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प्रश्न
उत्तर
Examples of potential energy:
(i) Water stored at a height in a reservoir.
(ii) A stretched spring.
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संबंधित प्रश्न
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B does the same in 15 s. Compare the Work done.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
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.
The work done on an object does not depend on ______.
Name the force acting away from the centre of circular path.
Is work done a scalar or a vector physical quantity?
Write an expression for work done by a force depends?
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
Fill in the boxe to show the corresponding energy transformation.
Is power a scalar or a vector quantity?
What should be the characteristic of a source of energy?
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
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 bucketful of water is to be drawn from a well ______ will be done when a ______ is applied to do this because there will be a ______ of water.
(displacement, work, force)
Who is the odd one out?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Food grains are getting dried in the sun.
Work done by this force at any instant is ______.
