Question

use the information below to answer the following question.

A traditional, double-seat chairlift can move1200 people in 1.00 hrs (with an average mass of 60.0 kg) up a ski hill. A high-speed quad chair can move 2400 people in 30.0 minutes up the hill. The upper terminal (top of the hill) is 100 m higher than the lower terminal (bottom of the hill).

1.The amount of power the quad-seat chair requires just to overcome gravity is ___x10⁴ W. (Give your answer with the correct number of sig digs and do not include units)

2.An electric motor has a power rating of 1.60 kW and operates at 75% efficiency. The amount of work that it can do in 1.0 hrs is ___x10⁶ J. Give your answer with the correct number of sig digs and do not include units)

Answer 1

1)

$$W=\frac{2400(60)(9.8)(100)}{30(60)}=7.84\cdot10^4W$$

2)

$$0.75(1600)=\frac{W}{3600}\\W=4.32\cdot10^6\ J$$