A ship, of mass 5000 tonnes, is moving through the sea at a constant speed of \(15 \mathrm {~km} \mathrm {~h} ^ { - 1 }\).
Calculate the momentum of the ship, in the form \(a \times 10 ^ { n }\), where \(0 \leq a < 10\) and \(n\) is an integer. State the units of your answer.
Given that there is a constant force of magnitude 4000 N acting against the ship due to air and water resistances,
find the rate, in kW , at which the ship's engines are working.