(a) How far does the boat coast? (b) How much time does it take for the boat to come to rest after the ...?

Question

A power boat of mass 480 kg is cruising at a constant speed of 8.9 m/s. The propeller provides a drive force of 765 N. The driver of the boat shuts off the engine, and the boat coasts to a halt. Assume-contrary to fact-that the resistive force due to the water is constant, independent of the boat's speed.

(a) How far does the boat coast?

(b) How much time does it take for the boat to come to rest after the engine is turned off?

Answer 1

The length of time that a boat takes to stop is dependent on its hull  shape and mass. A carrier can take up to a mile. Sailboats coast far longer than power boats.

Answer 2

I thought this would have depended on the wind and currents.

Answer 3

since they have no wheels they stop fast