Question

1. A boy of mass 50kg runs a set of steps of total height 10cm. calculate the work done (take g = 10ms - 2 ) 2. A 70kg man ascends a flight of stairs of height 4m in 7 seconds. Calculate the power expended by the man 3. A 40kg girl climbs up a stair and expends energy at the rate of 50W. calculate the time taken for her to reach a height of 20m 4. State the law of energy conservation 5. Give two applications of conduction, convection and radiation. 6. Give the major different between Radiation and other forms of energy transfer.

Answer 1

Answer:

don't know. .........

Answer 2

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