An elevator (North American English) or lift (Commonwealth English) is a type of cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.
In agriculture and manufacturing, an elevator is any type of conveyor device used to lift materials in a continuous stream into bins or silos. Several types exist, such as the chain and bucket elevator, grain auger screw conveyor using the principle of Archimedes' screw, or the chain and paddles or forks of hay elevators. Languages other than English, such as Japanese, may refer to elevators by loanwords based on either elevator or lift. Due to wheelchair access laws, elevators are often a legal requirement in new multistory buildings, especially where wheelchair ramps are not possible.
Some elevators can also travel horizontally in addition to the usual vertical motion.
Homework Statement
While an elevator of mass 2442 kg moves upward, the tension in the cable is 34.2 kN
Homework Equations
(a) What is the ?
The Attempt at a Solution
a= f/m
a= 34200N/2442kg =14.0
Homework Statement
You are standing on a bathroom scale inside an elevator. Your weight is 160 lb, but the reading of the scale is 123 lb.
(a) What is the magnitude and direction of the acceleration of the elevator?
? m/s2
(b) Can you tell whether the elevator is speeding up or slowing...
Homework Statement
Crates A and B are in an elevator, with Crate A on top of Crate B. The mass of crate A is greater than the mass of crate B. The elevator moves downward at constant speed. Compare the accelerations of Crates A and B.
I'm tempted to say there are equal, and both equal to...
Homework Statement
"A student whose weight is 500 Newtons stands on a scale in an elevator and records the scale reading as a function of time. The data is shown in the graph above. At time t=0, the elevator is at displacement x=0 with velocity v=0. Assume that the positive directions for...
I was thinking about the Space Elevator idea, and I think most of us can agree that as one goes higher up the the tower, the pull of gravity gets weaker and "centrifugal force" gets stronger (compared to one another), until the altitude of geosynchronous orbit, where the two become equal. So...
Homework Statement
Henry gets into an elevator on the 50th floor of a building and it begins moving at t = 0 s. The figure shows his apparent weight over the next 12 s where w1 = 520, w2 = 720, and w3 = 920.
The graph:
Begins at t=0 at w1 and goes in a horizontal straight line until...
A box with a 75 passenger inside is launched straight up into the air by a giant rubber band.
After the box has left the rubber band but is still moving upward, what is the passenger's apparent weight?
This is all the information that was given. The question prior to this one wanted to...
A hotel elevator ascends 200 meters with a maximum speed of v= 5.0 m/s. It has a constant (net) acceleration of a +/- 1.0m/s^2. This means that the bottom floor is at 0.0meters and the top floor is at 200 meters. At rest, the v=0. when going up, it fights against gravitational acceleration of...
Homework Statement
A 48 kg passenger rides in an elevator that starts from rest on the ground floor of a building at t = 0 and rises to the top floor during a 10 s interval. The acceleration of the elevator as a function of the time is shown in Fig. 3-32, where positive values of the...
A certain elevator cab has a total run of 199 m and a maximum speed is 313 m/min, and it accelerates from rest and then back to rest at 1.10 m/s2. (b) How long does it take to make the nonstop 199 m run, starting and ending at rest?
How do I approach part B?
Homework Statement
A hotel elevator ascends 200 m with a maximum speed of 4.8 m/s. Its acceleration and deceleration both have a magnitude of 1.0 m/s2.
(a) How far does the elevator move while accelerating to full speed from rest? (Answer in Meters)
(b) How long does it take to make the...
Homework Statement
why is it that you sometimes feel 'light' or 'heavy' while moving in a fast moving lift? A lift has a total maximum mass, including occupants of 1000kg. it is supported by steel ables. the maximum acceleration or deceleration of the lift in operation is 2.0ms^-2. How big is...
A particle of mass 0.2kg hangs from and ideal spring. In equilibrium, the spring is stretched by amount of 0.49cm. The spring is then suspended from the ceiling of a lift and hangs motionless relative to the lift as the lift descends with a constant velocity of 2.0m/s. The lift then suddenly...
Homework Statement
An elevator consists of an elevator cage and a counterweight attached to the ends of a cable that runs over a pulley. The mass of the cage (with its load) is 1200kg, and the mass of the counterweight is 1000kg. The elevator is driven by an electric motor attached to the...
in a problem where there is a 100kg bag placed on the floor of a 1000kg elevator, going up with an acceleration of 0.8m/s^2, what is the normal force applied on the bag by the elevator.
i thought that the normal force would be mg(using the mass 1100kg)-F(the force lifting the elevator) but...
[SOLVED] Elevator vs. Piston/Cylinder
In designing a reciprocating linear motion force, I have two approaches to the problem using a standard 1 horsepower motor. The travel is 2 feet forward and 2 feet backwords with a minimum force of 200lbs.
From calculations, each cycle of the...
Two masses are connected by a string and are hanging from the ceiling of an elevator like this:
[string 1]
|
[4kg mass]
|
[string 2]
|
[6kg mass]
Show the tension of each string in the following situations:
i) Stationary
ii) Moving up at 3m/s
iii) Moving down at...
A mass is attached to a spring supported from the ceiling of an elevator. We pull down on the mass and let it to vibrate. If the elevator starts to accelerate(fixed accelerate) upward,
1) How the maximum velocity changes?
2) How the amplitude changes?
3) How the total energy changes?
I...
Homework Statement
An elevator weighing 2100 N ascends at a constant speed of 8.0 m/s. How much power must the motor supply to do this?
Homework Equations
P = FvThe Attempt at a Solution
F = 2100 N
V = 8 m/s
P = (2100) * (8) = 16800
in significant figures that's 1.7 x 10^4 w
in kilowatts...
Today I was outside to get some grass for my rabbit. I took some yellow dandelions too, but as I entered the elevator I noticed a strange phenomenon. The elevators light was yellow (the typical light bulb) and when I looked at the flower of the dandelion it was yellow as you would exect it to...
I am doing a controls project in which I will try to control the speed of an elevator using a simplified model. The model is simply a motor connected to a pulley which moves the car up and down through a cable. The only difficulty I am having is estimating realistic parameters for the model. For...
Homework Statement
he cable of the 1,800 kg elevator cab in Fig. 8-51 snaps when the cab is at rest at the first floor, where the cab bottom is a distance d = 3.7 m above a cushioning spring whose spring constant is k = 0.15 MN/m. A safety device clamps the cab against guide rails so that a...
Homework Statement
A 523 kg elevator starts from rest. It moves upward for 3.79s with a constant acceleration until it reaches its cruising speed of 1.78 m/s.
The acceleration of gravity is 9.8 m/s^2.
Find the average power delivered by the elevator motor during the period of this...
Homework Statement
The cable of an elevator of mass M = 1920 kg snaps when the elevator is at rest at one of the floors of a skyscraper. At this point the elevator is a distance d = 15.6 m above a cushioning spring whose spring constant is k = 23100 N/m. A safety device clamps the elevator...
Bob is standing on an ordinary bathroom scale in an elevator. He glances down at the scale, and notes that the reading is greater than his weight. Consider the following situations:
(i) The elevator is traveling upward.
(ii) The elevator is traveling downward.
(iii) The elevator is...
Homework Statement
You've always wondered about the acceleration of the elevators in the 101-story-tall Empire State Building. One day, while visiting New York, you take your bathroom scale into the elevator and stand on it. The scale reads 150 lbs as the door closes. The reading varies...
An elevator of mass M = 300 kg hangs at the end of a long, thin steel cable: it has length L = 96 m and diameter d = 3 mm.
A minor earthquake shakes the entire building. After the quake passes, the elevator continues to bob up and down for a long time. What is the period of oscillation?
i used...
Homework Statement
Moving at a constant speed, an elevator lifts a 1200N package 10m in 3 sec. During this time, the impulse delivered to the package by the elevator floor is
a) zero
b) 12000 Nm up
c) 3600 Ns up
d) 12000 Ns up
Homework Equations
change in momentum = net Force*time...
Homework Statement
A pendulum of length L is suspended from the ceiling of an elevator. When the elevator is at rest the period of the pendulum is T. How does the period of the pendulum change when the elevator moves upward with constant acceleration? Explain. Homework Equations
T=2pi...
Hello, I am in a school group attempting to create a model of the "turbolift" from Star Trek (NERD ALERT!, i know) using magnetic forces. My group has already worked out the x and z axis of movement, but we are having trouble figuring out just how strong of a force we will need to lift, if we...
First of all, I know I've posted this already, but I didn't really understand the reply. I tried going back to the thread, but I can't find it anymore.
Homework Statement
A 750 kg elevator starts from rest. It moves upward for 3.00 s with constant acceleration until it reaches its cruising...
An elevator ascends from the ground with uniform speed. At time T_1 a boy drops a marble through the floor. The marble galls with uniform acceleration g = 9.8 and hits the ground T_2 seconds later. Find the height of the elevator at time T_1 .
So we use the following equations...
Homework Statement
A 750 kg elevator starts from rest. It moves upward for 3.00 s with constant acceleration until it reaches its cruising speed, 1.75 m/s.
(a) What is the average power of the elevator motor during this period?(b) How does this power compare with the motor power when the...
I need help getting started with this problem. Thanks.
Homework Statement
The acceleration of an elevator changes at a rate give by the function
http://img232.imageshack.us/img232/2739/mathzy2.jpg
Plot the position of the elevator assuming that its velocity at t=0 is zero and the elevator...
A 4500kg elevator moves upward 10m in a times of 3.8s
a) The minimum work done by the motor is
b) The minimum motor power rewuired is
a W=F* X
So F= m*a , that 4500kg * 3.8s = 171,000
therfore P= 171,000/10 = 17,100
Is this right?
A 700 kg elevator suspended by a cable accelerates upwards at 3 m/s^2. The force exerted by the cable on the elevator is?
(use g=10 m/s^2)
m=700 kg
a= 3.0 m/s^2
Fnet= 700 kg * 3.0 m/s^2
= 2,100.0 N Upward force
Fnet= 700 kg * 10 m/s^2
= 7,000.0 N Downward force...
Homework Statement
A man with a mass of 85.0 kg rides downward on an elevator.Initially the elevator accelerates downwards at 1.845 m/s^2 and eventually slows at 1.60 m/s^2 as it reaches the ground floor. Find the mans apparent weight as he starts down and as he reaches the ground floor...
[SOLVED] An Elevator and work
Homework Statement
The loaded cab of an elevator has a mass of 3.0 103 kg and moves 204 m up the shaft in 23 s at constant speed. At what average rate does the force from the cable do work on the cab? Answer in kW.
Homework Equations
Power is the dot...
Homework Statement
650kg elevator starts from rest. It moves upward for 3.00s with constant acceleration until it reches its cruising speed of 1.75m/s. What is the average power of the elevator motor during this period?
Homework Equations
use either force or conservation of energy...
[SOLVED] Gravitational Potential Energy
Homework Statement
Calculate the change in potential energy of a 77.2-kg man when he takes an elevator from the first floor to 24th floor, if the distance between floors is 4.05 m.
Homework Equations
Ug = mgy
The Attempt at a Solution
Ug =...
If an elevator accelerates upwards at say about 1.96m/s/s, and say I need to find what the minimum force is required to move the box while the elevator is in motion. Would I find the force of the elevator (using F=ma) moving upwards and add it to the boxes weight and then the total weight of the...
Homework Statement
The upward normal force exerted by the floor is 620N on an elevator passenger who weighs 650N.
Homework Equations
F=ma
The Attempt at a Solution
I am reviewing all the Homework assigned so, I do got the answers. :)
Anyways, the way I set this problem up...
Hi I just needed help with a question with 2 parts. I just need to know where to start and what formula is recommended for use.
For example:
Larry is standing on a scale in an elevator, the scale reads x. The elevator accelerates upwards at x m/s/s. The elevator weighs xx. How much does the...
Homework Statement
The cable of the 1800 kg elevator in Fig. 8-62 snaps when the elevator is at rest at the first floor, where the bottom is a distance d = 3.7 m above a cushioning spring whose spring constant is k = 0.15 MN/m. A safety device clamps the elevator against guide rails so that...
Homework Statement
A freight elevator weighing 3000 pounds is supported by a 12 foot long cable that weighs 14 pounds per linear foot. Approximate the work required to lift the elevator 9 feet by winding the cable onto a winchHomework Equations
W = int(f)dyThe Attempt at a Solution
The work...
Pretty sure I got it right just going to ask you guys to make sure.
Homework Statement
An elevator with a mass of 1.10e3 accelerates upward at 0.45 m/s squared. What is the force acting on the elevator's support cable?
Homework Equations
F=ma
The Attempt at a Solution
The 9.8...
A stationary elevator and its contents have a combined mass of 3000Kg. The elevator is suspended by a single cable. (Assume three significant digits.)
Draw a free-body diagram of the elevator and calculate the values of all the forces that are acting on it when at rest.
If the elevator is...
For elevator problem in Force, I have some confusions about basic concepts. Here give an example: an elevator is to be designed so that the maximum acceleration is 0.068g. Here why would the elevator's acceleration smaller than the gravity, then can it still pull the whole elevator up? Or...
A stationary elevator and its contents have a combined mass of 3000Kg. The elevator is suspended by a single cable. (Assume three significant digits.)
Draw a free-body diagram of the elevator and calculate the values of all the forces that are acting on it when at rest.
If the elevator is...
Homework Statement
A 545N physics student stands on a bathroom scale in an 847kg (including the student) elevator that is supported by a cable. As the elevator starts moving, the scale reads 427N.
Find the magnitude of the acceleration of the elevator.
Find the direction of the...