The power that a person develops when a bucket of water is evenly lifted from a well 10 meters deep is 20 watts.

The power that a person develops when a bucket of water is evenly lifted from a well 10 meters deep is 20 watts. Find the volume of water in a bucket if it is known that the mass of an empty bucket is 1 kilogram, the lifting time is one minute. Take the density of water equal to 1000 kilograms per cubic meter.

h = 10 m.

g = 10 m / s2.

N = 20 W.

mw = 1 kg.

t = 1 min = 60 s.

ρ = 1000 kg / m3.

V -?

The volume of water raised in a bucket V is expressed by the formula: V = m / ρ, where m is the mass of water in the bucket, ρ is the density of water.

m = V * ρ.

Let us express the power of a person when lifting a bucket of water: N = A / t.

A = (mb + m) * g * h.

N = (mv + V * ρ) * g * h / t.

mv + V * ρ = N * t / g * h.

V * ρ = N * t / g * h – mv.

V = N * t / ρ * g * h – mv / ρ.

V = 20 W * 60 s / 1000 kg / m3 * 10 m / s2 * 10 m – 1 kg / 1000 kg / m3 = 0.011 m3 = 11 liters.

Answer: there was water in the bucket with a volume of V = 11 liters.