Advertisements
Advertisements
Question
State two factors on which power spent by a source depends. Explain your answer with examples.
Advertisements
Solution
A source's use of power depends on two things:
- The amount of work done by the source, and
- The time taken by the source to do the said work.
Example: Should a coolie A take one minute to raise a load to a bus roof, and another coolie B take two minutes to do the same, Both coolies accomplish the same amount of work; however, because coolie A works more quickly, the power expended by him is double that of coolie B.
APPEARS IN
RELATED QUESTIONS
A coolie X Carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head move the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.
Is it possible that no transfer of energy may take place even when a force is applied to a body?
State the factors on which moment of force about a point depends.
State the condition when a force produces
(i) linear motion.
(ii) rotational motion, in a body.
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes. Compare:
- the work, and
- power developed by them.
State and define the unit of force in the S.I. system.
State two conditions for work to be done.
A man weighing 700 N runs up a flight of 15 steps, each 20 cm high, in 5 seconds. Calculate the power of the man.
