Advertisements
Advertisements
प्रश्न
State the law of conservation of energy.
उत्तर
According to the law of conservation of energy, energy can neither be created nor can it be destroyed. It only changes from one form to another.
APPEARS IN
संबंधित प्रश्न
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
Power spent by a body depends on the time for which it does work.
No work is done by a force if the body
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The loss in potential energy of the body,
A vessel containing 50 kg of water is placed at a height 15 m above the ground. Assuming the gravitational potential energy at ground to be zero, what will be the gravitational potential energy of water in the vessel? (g = 10 m s-2)
What do you mean by degradation of energy?
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
Is the motion of moon around the earth in circular path an accelerated motion?
How many joules are there in 1 mega joule?
Is power a scalar quantity?
Distinguish between work and power.
What do you understand by 'potential energy' and 'Kinetic energy'? Give three examples of each to illustrate your answer.
Fill in the boxe to show the corresponding energy transformation.
A coolie, with a load of 30 kg on his head, walks on the platform. If he walks a distance of 60 m, what is the work done by him?
In the following case write yes, if the work is being done and no if no work is being done.
A boy climbing up a staircase.
Calculate the work done when:
A 5 kg weight is lifted 10 m vertically. (g = 9.8 m/s2)
An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).
