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प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Food grains are getting dried in the sun.
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उत्तर
The grains of corn are drying in the heat of the sun; here, also, no work is being done because the grains are stable in their place. There is no displacement in them.
संबंधित प्रश्न
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
What are the units of (a) work, and (b) energy?
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.
Is power a scalar quantity?
Name the physical quantity associated with the 'rate of doing work'.
How much energy is gained by a box of mass 20 kg when a man, runs carrying the box with a speed of 3 m/s-1 to catch the bus?
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
Calculate the work done when:
A 5 kg weight is lifted 10 m vertically. (g = 9.8 m/s2)
