Advertisements
Advertisements
प्रश्न
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 ms–1?
उत्तर
One watt is the power of an agent which does work at the
rate of one joule per second. 1 kilowatt = 1000 watt
= 1000 joule per second (v 1 W = 1 J s−1)
Mass of the car, m = 150 kg
Power developed by engine per kg = 500 W
Total power developed by engine,
P = 500 W x 150
= 75000 W
Speed of car, v = 20 m s−1 Power, P = Fv
=> Force exerted in moving the car, f = `"P"/"v"`
= `(75000"W")/(20 "ms"^-1)`
= 3750 N
APPEARS IN
संबंधित प्रश्न
State the energy changes in the following while in use An electric bulb.
State the energy changes in the following while in use An electric oven.
State the energy changes in the following while in use A loudspeaker .
Fill in the blank
Green plants convert _________ energy into chemical energy.
Energy can exist in several forms and may change from one form to another. State the energy changes that occur in a car going uphill.
Energy can exist in several forms and may change from one form to another. State the energy changes that occur in the Charging of a battery.
State the energy changes in the following case while in use:
a steam engine
Explain conservation of energy.
Avinash can run with a speed of 8 m s–1 against the frictional force of 10 N, and Kapil can move with a speed of 3 m s–1 against the frictional force of 25 N. Who is more powerful and why?
State the energy changes in the following case while in use:
An electric cell in a circuit
