♥ C) 94%
♥ If the work put into a lever is 930 joules and the work accomplished is 870 joules, the efficiency of the lever is 94%.
♥ <span>870/930=93.5
</span>♥ And rounded you get 94.
Answer:
The power output of the first motor is, P = 2.0 x 10⁴ watts
Explanation:
Given data,
The height of the building, h = 10 m
The mass of the elevator, m = 1000 kg
The time duration of the motor to do this work, t = 5.0 s
The force acting on the elevator,
F = m x g
= 1000 x 9.8
= 9800 N
The work done by the elevator,
W = F x h
= 9800 x 10
= 98000 J
The power output of the first motor,
P = W / t
= 98000 / 5
= 19600 watts
= 1.96 x 10⁴ watts
Hence, the power output of the first motor is, P = 2.0 x 10⁴ watts
Well her speed and velocity are the same 8 kilometers per hour<span />
