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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?
Power spent by a body depends on the time for which it does work.
Differentiate between energy and power.
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
What do you mean by degradation of energy?
What are the units of (a) work, and (b) energy?
What happens to the work done when the dispacement of body is at right angles to the direction of force acting on it? Explain your answer.
Determine the amount of work done when an object is displaced at an angle of 30° with respect to the direction of the applied force.
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
State the amount of work done by an object when it moves in a circular path for one complete rotation. Give a reason to justify your answer.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
A block of mass 30 kg is pulled up a slope, as shown in diagram with a constant speed, by applying a force of 200 N parallel to slope.
A and B are initial and final positions of block.
(i) Calculate the work done by force in moving the block from A to B.
(ii) Calculate P.E. gained by block. [g=10ms-2]
One labourer carried four pans of road metal through a distance of 100 metres. If he carries two pans of road metal through a 200 metre distance ______ work will be done.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
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.
