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प्रश्न
Energy can exist in several forms and may change from one form to another. State the energy changes that occur in the Explosion of crackers.
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उत्तर
Chemical energy changes into heat, light and sound energy.
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संबंधित प्रश्न
State the energy changes in the following while in use An electric oven.
Energy can exist in several forms and may change from one form to another. State the energy changes that occur in a loaded truck when started and set in motion.
Energy can exist in several forms and may change from one form to another. State the energy changes that occur in photosynthesis in green leaves.
State the energy changes in the following case while in use:
loudspeaker
A metal ball of mass 2 kg is allowed to fall freely from rest from a height of 5 m above the ground. What happens to the mechanical energy after the ball hits the ground and comes to rest?
Choose the odd one:
Avinash can run with a speed of 8 m s–1 against the frictional force of 10 N, and Kapil can move with a speed of 3 m s–1 against the frictional force of 25 N. Who is more powerful and why?
The velocity of a body moving in a straight line is increased by applying a constant force F, for some distance in the direction of the motion. Prove that the increase in the kinetic energy of the body is equal to the work done by the force on the body.
Is it possible that an object is in a state of accelerated motion due to external force acting on it, but no work is being done by the force? Explain it with an example.
Four men lift a 250 kg box to a height of 1 m and hold it without raising or lowering it.
(a) How much work is done by the men in lifting the box?
(b) How much work do they do in just holding it?
(c) Why do they get tired while holding it? (g = 10 m s–2)
