How long would it take a 4,560 watt motor to raise a 166 kg piano to an apartment window 15 meters above the ground?

Explanation:

We need the power equation here:

P = W/t where W is work and is defined as

W = F*displacement.

Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:

w = mg so

w = 166(9.8) so

w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:

and isolating the unknown:

so

t = 5.3 seconds

increases it