#1 An elevator ascends from the ground floor to the 10th floor, a height of 36 m

Question

#1 An elevator ascends from the ground floor to the 10th floor, a height of 36 m , in 35 s. The mass of the elevator and passengers is 850 kg .
-What's the power necessary to lift the elevator? (Your answer is greater than the actual power needed because elevators are counterweighted, thus reducing the work the motor needs to do.)

#2 You're trying to decide whether to buy an energy-efficient, 225 -W refrigerator for $1150 or a standard, 425 -W model for $850. The standard model will run 20% of the time, but better insulation means the energy-efficient model will run 11% of the time.
-If electricity costs 9.5cent/kWh, how long would you have to own the energy-efficient model to make up the difference in cost? Neglect interest you might earn on your money.

#3 You're assisting a cardiologist in planning a stress test for a 80 kg patient. The test involves rapid walking on an inclined treadmill, and the patient is to reach a peak power output of 350 W.
-If the patient's maximum walking speed is 7.0 km/h , what should be the treadmill's inclination angle?

Please help! Even if you can only answer one of the questions, any help is greatly appreciated!

Explanation / Answer

you have asked 3 different questions.As per chegg guidelines i can only answer one.Please raise different question for others

1)power = work / time

power = mgh / t

=850*9.8*36/35

=8568watt

power=8.568kwatt---answer 1

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