In homes with more floor elevators are used. For passenger transport, the most commonly used traction elevator counterweight. The top of the shaft
engine room with the engine. The car is suspended on a rope, which is guided up over two pulleys to the counterweight.

Consider lift-enabled load Mmax = 300 kg
car weight mk = 500 kg
weight counterweight mz = 650 kg. Cabin moves at the speed
v0 = 1.2 m/s. The total efficiency of power is k =75%.

a) Explain what affects the efficiency of the system and the reason for using a counterweight.

b) Determine the power P1 engine lift if you summon an empty cabin residents of the upper floors, which moves down the speed of v0.
c) Determine the power P2 engine lift when a group of citizens with a total mass M = 250 kg conveys speed v0 upwards.

In which of these cases b), c) the need for more power?
g = gravitational constant 10 N/kg

Correct answer:

P1 =  2.4 kW
P2 =  1.6 kW

Step-by-step explanation:

P1=mkmzgv075100 P1=500650101.275100=2.4 kW
P2=mk+Mmzgv075100 P2=500+250650101.275100=1.6 kW P1>P2

Did you find an error or inaccuracy? Feel free to write us. Thank you!

Tips for related online calculators
Our percentage calculator will help you quickly calculate various typical tasks with percentages.
Do you want to convert velocity (speed) units?
Do you want to convert time units like minutes to seconds?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: