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संबंधित प्रश्न
When do we say that work is done?
A coolie does no work against the force of gravity while carrying a luggage on a road.
Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.
A boy tries to push a truck parked on the roadside. The truck does not move at all. Another boy pushes a bicycle. The bicycle moves through a certain distance. In which case was the work done more : on the trick or on the bicycle? Give a reason to support your answer.
In case of negative work, the angle between the force and displacement is :
Does the earth move around the sun with a uniform velocity?
No work is done by a man moving on a horizontal road while carrying a box on his head. Explain.
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
Fill in the boxe to show the corresponding energy transformation.
What should be the characteristic of a source of energy?
Explain, why submarines are able to dive underwater as well as a sail on the surface of the water?
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
What is work?
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
