Define watt. Express kilowatt in terms of joule per second. A 150 kg car engine develops 500 W for each kg. What force does it exert in moving the car at a speed of 20 m sβ1?
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Soln:
Power of an object which does work at 1 Joules/sec is called watt
1 watt= π±ππππ
ππππππ
1 kilowatt= 1000watts=1000J/sec mass of car = 150kg
power for each kg=500x 150=7500w
speed=20m/s power=Force x v
β΄force=power/v 7500
20
=3750N
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