# physics

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A power boat of mass 465 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?

• physics -

friction is 765N.

acceleration during slowing is F/mass=765/m

Vf^2=Vi^2+2ad where a= -765/m solve for d.

average velocity= 8.9m/s

time= distance/8.9m/s

• physics -

Wow how do you not know this

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