Answer:
a) 0.47MW
b) 39.24%
Explanation:
In order to find the power needed for the elevator to operate at its maximum capacity, we can make use of the following formula:
P=Fv
where P is the power, F is the force and v is the velocity.
The force the elevator must carry can be calculated with the following formula:
F=mg
where m is the mass of the elevator and g is the acceleration of gravity, so:
[tex]F=(8000 kg)(9.81 m/s^{2})[/tex]
F=78 480 N
so now we can make use of the power formula:
P=Fv
P=(78 480N)(6 m/s)
P=470 880W
P=0.47W
b)
In order to find the efficiency, we will suppose that the generator can generate a maximum of 0.47 W so we use the following formula:
[tex]efficiency = \frac{P_{in}}{P_{out}}*100\%[/tex]
[tex]efficiency=\frac{0.470880}{1.2}*100\%[/tex]
efficiency=39.24%