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प्रश्न
Does the earth move around the sun with a uniform velocity?
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उत्तर
No, the earth moves round the sun with a variable velocity. Since the direction of motion changes at each and every point the velocity becomes variable.
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संबंधित प्रश्न
How is work related to energy?
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B does the same in 15 s. Compare the work done.
The power of a motor is 40 kW. At what speed can the motor raise a load of 20,000 N?
What should be the angle between the direction of force and the direction of motion of a body so that the work done is zero?
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
A body does 20 J of work in 10 s. What is its power?
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.
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
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.
