Find the useful power output (in W) of an elevator motor that lifts a 2600 kg load a height of 45.0 m in 12.0 s, if it also increases the speed from rest to 4.00 m/s. (a) 3.58×104 W
(b) 4.93×104 W
(c) 6.21×104 W
(d) 7.45×104 W