Advertisements
Advertisements
प्रश्न
A pump raises water by spending 4×105J of energy in 10s. Find the power of the pump.
Advertisements
उत्तर
Energy spent = w = 4 × 105J
Time taken = 10s
Power = Energy / Time
P = `(4 × 10^5)/10` = 4×104 W
APPEARS IN
संबंधित प्रश्न
A body is moving unidirectionally under the influence of a source of constant power. Its displacement in time t is proportional to ______.
The blades of a windmill sweep out a circle of area A.
- If the wind flows at a velocity v perpendicular to the circle, what is the mass of the air passing through it in time t?
- What is the kinetic energy of the air?
- Assume that the windmill converts 25% of the wind’s energy into electrical energy, and that A = 30 m2, v = 36 km/h and the density of air is 1.2 kg m–3. What is the electrical power produced?
Power P= ............ /time taken.
Match the following
| column A | Column B |
| A stone at a height | power |
| A Moving ball | joule |
| Energy | work done in 1 s |
| Power | potential energy |
| Watt | kinetic energy |
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.
An electric pump has 2 kW power. How much water will the pump lift every minute to a height of 10 m?
A bullet of mass 20 g strikes a pendulum of mass 5 kg. The centre of mass of the pendulum rises a vertical distance of 10 cm. If the bullet gets embedded into the pendulum, calculate its initial speed.
Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine? (g = 10 m/s2)
Name the quantity which is measured in eV.
At any instant of time t, the displacement of any particle is given by 2t – 1 (SI unit) under the influence of force of 5N. The value of instantaneous power is (in SI unit):
