Elevator

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

Result

P1 =  2400 kW
P2 =  1600 kW

Solution:

Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

To solve this example are needed these knowledge from mathematics:

Do you want to convert mass units?

Next similar examples:

1. Three friends
Danica, Lenka and Dalibor have altogether 96 kg. Lenka weighs 75% more than Dalibor and Danica weighs 6 kg more than Dalibor. Determine the weight of Danice, Lenka and Dalibor.
2. Vegan shop
To the shops brought together 23.2 kg of goods, fruits, vegetables and nuts. fruit was 4.7 kg more than vegetables, nuts was 1.5 kg less than the fruit. Determine the amount of fruits, vegetables and nuts.
3. Three workshops
There are 2743 people working in three workshops. In the second workshop works 140 people more than in the first and in third works 4.2 times more than the second one. How many people work in each workshop?
4. Car
At what horizontal distance reaches the car weight m = 1534 kg speed v = 85 km/h when the car engine develops a tensile force F = 1691 N. (Neglect resistance of the environment.)
5. Locomotive
Locomotive pulled a train permanent load of 200 kN horizontally along the track of 5km. What work it done?
6. Family
Family has 4 children. Ondra is 3 years older than Matthew and Karlos 5 years older than the youngest Jane. We know that they are together 30 years and 3 years ago they were together 19 years. Determine how old the children are.
7. Father 7
Father is 6 times older than his son. After 4 years, the father will only be 4 times older. What are their present ages?
8. AP - simple
Determine the first nine elements of sequence if a10 = -1 and d = 4
9. Confectionery
The village markets have 5 kinds of sweets, one weighs 31 grams. How many different ways a customer can buy 1.519 kg sweets.
10. Reference angle
Find the reference angle of each angle:
11. Sequence
Write the first 6 members of these sequence: a1 = 5 a2 = 7 an+2 = an+1 +2 an
12. Theorem prove
We want to prove the sentense: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
13. Trigonometry
Is true equality? ?
14. Sequence
Write the first 7 members of an arithmetic sequence: a1=-3, d=6.
15. Teams
How many ways can divide 16 players into two teams of 8 member?
16. Examination
The class is 21 students. How many ways can choose two to examination?
17. Sequence 2
Write the first 5 members of an arithmetic sequence a11=-14, d=-1