150 kW: Assume there is no loss of force due to air resistance. What is the greatest average speed at which this engine could lift a mass of 2.00 t? A 1250-kg race car accelerates uniformly from rest to 30.0 m/s in 4.00 s on a horizontal surface with no friction. What must be the average power output of its motor? Each car in a freight train experiences a drag force of 6.00 × 10^2 N due to air resistance. (a) If the engine of the train is to pull a train of 75 cars at a constant speed of 72.0 km/h, what power is required to move the cars? (b) If the engine operates at 15.0% efficiency, what must be the power generated by the engine to move these cars?
Answers:
1. 11.0 kW
2. 7.65 m/s
3. 141 kW
4. (a) 900 kW
(b) 6.00 × 10^3 kW