The thrust of a certain boat's engine generates a power of 10 kW as the boat moves at constant speed 10 % through the water of a lake. The magnitude of the drag force that is exerted on the boat's hull as it is moving through the water is directly proportional to the boat's speed and is given by the equation F = re. The increase in power needed for the boat to move through the lake at a constant speed of 12 g is (A) 0 (a) zooow (c; mow (m 12,000w (E) 14,400W Pulley with Pulley with Engine Engine vi mo Figure 1 Figure 2 m Figure 1 , an engine that delivers power P is attached to a pulley that hits a box of mass mg a vertical distance of ya at a constant speed in time to. If, as shown in Figure 2 the engine again delivers power P. how long would it take the engine to raise a box of mass 3mg the same vertical distance ya at a constant speed? on its (13} in (C) Jim (D) 3n (E) 9n An eleotrical motor provides {1.50 W of mechanical power. How much tilne will it take the motor to lift a 0.1 kg mass at constant speed from the oor to a shelf 2.0 m above the floor? 5. A motor rated with power P is used to litl an object of weight at constant speed to a height H in time t. The work done in lifting the box is IV. A motor rated with power 2P is used to lift the same object to the same height H in time t3. The new work done in lifting the box is W2. Which of the following claims correctly describes the relationships between the two times and two values of work done and is supported with appropriate reasoning? {A} W; 3 W and t2 4: t. because the more-powerful motor can do more work and do the work faster. (B) W2 > W and t2 W and 2