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प्रश्न
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उत्तर
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संबंधित प्रश्न
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 woman pulls a bucket of water of total mass 5 kg from a well which is 10 s. calculate the power used by her.
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.
What are the advantages and disadvantages of using solar cells for producing electricity?
A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s2, find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.
________ is said to be done when a force is acting on it.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Suma is swimming in a pond.
