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प्रश्न
उत्तर
Potential energy of a body depends upon:
(i) Mass of the body
(ii) Acceleration due to gravity
(iii) Height of the body
APPEARS IN
संबंधित प्रश्न
When do we say that work is done?
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
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?
Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.
State two conditions when no work is done by a force.
When is work said to be done by a force?
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
In case of negative work, the angle between the force and displacement is :
Name five appliances or machines which use an electric motor.
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Is work done a scalar or a vector physical quantity?
Define 'joule'.
A boy of mass m climbs up a staircase of vertical height h.
- What is the work done by the boy against the force of gravity?
- What would have been the work done if he uses a lift in climbing the same vertical height?
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
Fill in the boxe to show the corresponding energy transformation.
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
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?
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
Work done by this force at any instant is ______.
