The aircraft carrier ?John F. Kennedy? has mass 7.4 × 107 kg. When its engines are developing their full power of 280,000 hp, ?the John F. Kennedy? travels at its top speed of 35 knots (65 km/h). If 70% of the power output of the engines is applied to pushing the ship through the water, what is the magnitude of the force of water resistance that opposes the carrier’s motion at this speed?
Solution 58E Step 1: We know that 1 horsepower = 746 watts. 65 km/h = 18.1 m/s.