Advertisements
Advertisements
प्रश्न
Give an example
Light energy changes to electrical energy.
Advertisements
उत्तर
Solar cell
APPEARS IN
संबंधित प्रश्न
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 coolie is moving on a road with a luggage on his head. Does he perform work against the force of gravity? Give reason for your answer.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
Explain by an example that a body may possess energy even when it is not in motion.
P, Q and R are three forces which act as shown in fig.
The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
Give two examples of work done.
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
In the following case write yes, if the work is being done and no if no work is being done.
A coolie standing with a heavy load on his head
What is work?
