Average Power

Question

An electric pump raises 300 kg of water from a well to an overhead tank located 10 m above the water surface in exactly 60 s. Assuming no losses, what is the average power delivered by the pump?

RankGuru · Accepted Answer

Average power is the rate at which work is done, defined as $P_{avg} = W/t$, where the work done against gravity to lift the water equals its gain in gravitational potential energy. Lifting the water at steady speed requires work $W = mgh$, after which dividing by elapsed time gives the power. Taking $g = 10	ext{ m/s}^2$, the work is $W = 300 	imes 10 	imes 10 = 30000	ext{ J}$. Dividing by the time, $P_{avg} = 30000 / 60 = 500	ext{ W}$. The option 300 W ignores the height factor and divides incorrectly. The option 5000 W omits the division by time entirely, reporting the work scaled wrongly. The option 50 W underestimates by an order of magnitude through a misplaced decimal. This is the NCERT definition of average power as work per unit time. As a unit check, joules divided by seconds gives watts, and a half-kilowatt pump for this modest lifting task is physically reasonable.

Average Power

Select the correct option:

🔒 Solution Hidden from View

More work, energy and power Practice Questions

A rubber ball is dropped from a height of 2 m onto a hard floor and rebounds to a height of 1.28 m a...

A satellite moves in a perfectly circular orbit around the Earth under the gravitational pull direct...

A cyclist of total mass 70 kg rides up a slope inclined at 30 degrees to the horizontal at a steady ...

A small stone tied to a string is whirled in a vertical circle of radius 2 m. What is the minimum sp...

Two bodies of different masses possess the same magnitude of linear momentum while moving in a strai...

A ball is thrown vertically upward and returns to the same height from which it was launched on a wi...

A stone of mass 0.5 kg is dropped from rest at a height of 8 m above the ground. Ignoring air resist...

A weightlifter raises a barbell of mass 80 kg from the floor to a height of 2 m above the floor in 4...

A 2 kg lump of clay moving at 6 m/s strikes and sticks to a 4 kg block initially at rest on a fricti...

A car engine delivers a constant power of 50 kW while the car moves at a steady speed of 25 m/s alon...

A wooden crate of mass 10 kg is dragged 5 m up a rough incline by a force, and friction exerts a con...

Which of the following statements correctly distinguishes a conservative force from a non-conservati...

About This Question

Solution