MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Find the useful power output (in W) of an elevator motor that lifts a 2700 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. Note that the total mass of the counterbalanced system is 10,000 kg-so that only 2700 kg is raised in height, but the full 10,000 kg is accelerated. (Enter a number.) theorem A DE 10126.25 W OK - AKE (b) What does it cost (in cents), if electricity is $0.0900 per kW . h? (Enter a number.) cents 2 700 () (454 )-0 do- 1/9% + 1 ( 2700 ) (4)20 = 21600 11 919/50 - 2100