Advertisements
Advertisements
प्रश्न
It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the power spent by then.
Advertisements
उत्तर
Power = `"Work done"/"Time taken "` = `"Energy" /"Time"`
= `"Power of A "/ "Power of B"` = `(" Energy "/ t_1 )/("Energy "/ t_2)`
= `1/t_1` ' `t_2/1` =`15/20`
= `3/4` = 3 : 4
APPEARS IN
संबंधित प्रश्न
Define power.
A ball with a velocity of 5 ms−1 impinges at an angle of 60˚ with the vertical on a smooth horizontal plane. If the coefficient of restitution is 0.5, find the velocity and direction after the impact.
A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency, the work done by the motor in one rotation will be
Calculate the power of a crane in watts, which lifts a mass of 100 kg to a height of 10 m in 20s.
Sand is being dropped from a stationary dropper at a rate of 0.5 kgs-1 on a conveyor belt moving with a velocity of 5 ms-1. The power needed to keep belt moving with the same velocity will be ______.
Calculate the power spent by a crane while lifting a load of mass 2000 kg, at velocity of 1.5 ms-1. (g = 10 ms-2)
Unit of power used in mechanical engineering is ______.
Name the quantity which is measured in kW.
Name the quantity which is measured in Wh.
Name the quantity which is measured in eV.
