Elevator Definition and 561 Threads

Homework Statement A lamp hangs vertically from a cord in a descending elevator that decelerates at 1.4 m/s2. (a) If the tension in the cord is 56 N, what is the lamp's mass? (b) What is the cord's tension when the elevator ascends with an upward acceleration of 1.4 m/s2? Homework...

Homework Statement A ball of mass M is suspended by a thin string (of negligible mass) from the ceiling of an elevator. The vertical motion of the elevator as it travels up and down is described in the statements below. Indicate for each of the situations described the relation between value...

Homework Statement A 56.0 kg girl weighs herself by standing on a scale in an elevator. What is the force exerted by the scale when the elevator is descending at a constant speed of 10 m/s? What is the force exerted by the scale if the elevator is accelerating downward with an acceleration...

A 62-kg girl weighs herself by standing on a scale in an elevator. What does the scale read when the elevator is ascending at 11 m/s but its speed is decreasing by 5 m/s in each second? I'm not really sure where to begin.

A bolt comes loose from the bottom of an elevator that is moving upward at a speed of 6.38 m/s. The bolt reaches the bottom of the elevator shaft in 3.85 s. How high up was the elevator when the bolt came loose? I integrated 6.38 to get the position equation and plugged in 3.85. However...

Homework Statement A 22,500N elevator is to be accelerated upward by connecting to it a counterweight using a light cable passing over a solid uniform disk-shaped pulley. There is no appreciable friction at the axle of the pulley, but its mass is 875kg and it is 1.50 m in diameter. (a) How...

Hello all, I have probably a simple question for mechanical engineers. I would like to know the energy efficiency of real world freight elevators, going up with a speed of one meter per second. How about the best elevator's efficiency I could expect?

Homework Statement A scale is placed in a normal elevator on earth. A person with a mass of 60kg steps onto the scale. What force would be exerted on the person by the scale during the following occurances? -Moves up at constant speed -Slows at 2.0m/s/s while moving upwards -Speeds up...

Safety engineers estimate that an elevator can hold 20 persons of 75kg average mass. The elevator itself has a mass of 500kg. Tensile strength tests show that the cable supporting the elevator can tolerate a maximum force of 29600 N. What is the greatest acceleration that the elevator's motor...

Homework Statement Luke stands on a scale in an elevator which has a constant acceleration upward. The scale reads 0.968 kN. When Luke picks up a box of mass 18.6 kg, the scale reads 1.215 kN. (The acceleration remains the same.) Calculate the acceleration of the elevator (enter first). Is it...

hi, i m currently working on a radio controlled miniature aircraft for a local competition,,,,,,but i don't know how to calculate the torque required for the rudder & elevator motors.fuselage is about 200cms.airflow is abt 8-10m/s :confused: :confused: :confused: :confused: :confused...

hi, i am required to find the spring constant of the spring(s) below a typical elevator, you know the big metal springs locater underneath the elevator when it lands on the ground floor right. i have to find the spring constant/stiffness of the springs. anyone knows how to go about doing it...

A system of pulleys is used to lift an elevator that weighs 3900 Newtons. The pulley system uses 9 ropes to support the load. How far would 10700 joules of input work lift the elevator? Assume the pulley system is frictionless. Homework Equations w=fd f=ma w=mg The Attempt at a Solution w=fd...

An elevator cable breaks when a 920kg elevator is 28 m above a huge spring (k=2.2 x10^5 N/m) at the bottom of the shaft. Calculate a) the work done by gravity on the elevator before it hits the spring b) the speed of the elevator just before striking the spring and c) the amount of...

Homework Statement A skier of mass 69.7 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him a distance of 59.8 m up a 29.9° slope (assumed frictionless) at a constant speed of 1.90 m/s? (b) A motor of what power is required to perform this task? hp...

Homework Statement A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.78 of the person’s regular weight. a. Calculate the acceleration of the elevator. b. Find the direction of acceleration. Homework Equations...

Homework Statement An elevator with 1300 kg accrlerate from 0 m*s^-1 to 1.5 m*s^-1 in 2 s. After that, he drives further with a constant velocity of 1.5 m*s^-1. One must add a frictional force of 637,65 N. The questions are: 1. How much work is needed to accelerate the elevator? 2. How...

Force Of Man On Elevator Homework Statement An 65- kg man stands in an elevator. What force does he exert on the floor of the elevator under the following conditions? The elevator is stationary. Answer:637.65N The elevator accelerates upward at 2.3 m/s2. Answer:787.15N The elevator...

This is a different take on an elevator problem: An elevator and contents have a mass of 300kg and travels at 2.5 m/s during normal operation. The elevator's cables break and begins to free-fall. You need to stop the elevator and the max allowed deceleration is 4m/s^2. There is 0.05m...

I need a little help with this problem. I know what the answer is, but not how to get it. --- A passenger in an elevator has a mass of 100 kg. Calculate the force in Newtons exerted on the passenger by the elevator if the elevator is moving upward with an acceleration of 30 cm/s^2. ---...

I got a list of problems that will be on some of our exams soon, and i don't know how to do a few of them, here's one. a 60kg passenger standing on a scale in an elevator notes that the scale's maximum reading is 800 Newtons when the elevator accelerates upward. the scales minimum reading is...

I need some help designing a Digital elevator simulation using multi media logics. I need some help and guidelines as to how I should get the thruth diagrams, kmaps and the circuit going. I am required to design a digital circuit which has applications in elevator style controls. My circuit...

A student, standing on a scale in an elevator at rest, sees that his weight is 840 N. As the elevator rises, his weight increases to 1050 N, then returns to normal. When the elevator slows to a stop, his weight drops to 588 N. Determine the acceleration at the beginning and end of the trip...

how does the acceleration used in the formula f=ma change when the acceleration changes. you start at 9.8 m/s2. you get in an elevator or you move upward, changing the acceleration. how does acceleration due to gravity change? increase or decrease? thanks

I recently had an exam in my 2nd year dynamics course that included a question concerning a Space Elevator. My view on this question (or the answer to this question) seems to be different than my instructor's. I was hoping to get some of your thoughts so I could get a better understanding...

Hello, I am a junior in high school now taking AP Physics B. I'm stuck on a series of questions regarding force: 1. Assume you are on a planet similar to Earth where the acceleration of gravity is 10m/s^2 and the positive directions for displacement velocity and acceleration are upward. At...

Can someone tell me what I'm doing wrong here? When you weigh yourself on good old terra firma (solid ground), your weight is 126 lb. In an elevator your apparent weight is 118 lb. What are the direction and magnitude of the elevator's acceleration? I have Wa = W-ma = mg-ma Wa=118lb...

hey everyone, sheesh, our professor has us do our homework online, and I SWEAR my answer is right, but apparently it isnt. Here is the question: You leave the doctors office after your annual checkup and recall that you weighed 684N. You then step onto an elevator with a scale. Find the...

Intro: A physics student of a mass 59.3kg is standing on a scale in an elecator. The scale shows the magnitude of the upward normal force (in Newtons) on the student, this value is called the apparent weight. What is the reading on the scale when the elevator: Questions a) has a constant...

:confused: I am having trouble answering this question...what is the answer?! HELP Suppose you are in an elevator that is moving upward with a constant velocity. A scale inside the elevator shows your weight to be 600 N. (a) Does the scale register a value that is greater than, less than...

Two blocks are fastened to the ceiling of an elevator. The elevator accelerates upward at 1.70 m/s2. The blocks both have a mass of 11.5 kg. Find the tension in each rope. ______________________ ....| ....| ....| ...__________ ...|...| ...|...| ....| ....| ....| ...__________...

Hey guys! I feel like this should be an easy problem... Two blocks are fastened to the ceiling of an elevator. Each block has a mass of 10 kg. The elevator accelerates upward at 2 m/s^2. Find the tension in each rope. My prof drew a picture

A suitcase (mass m=16kg) is resting on the floor of an elevator. The part of the suitcase in contact with the floor measures 0.50m by 0.15m. The elevator is moving upward, the magnitude of its acceleration being 1.5m/s^2. What pressure (in excess of atmospheric pressure) is applied to the...

I have a question. If a person is in an elevator, and the elevator is accelerating down faster than the gravitational acceleration on the person, then what would happen to the person? Is he going to hit the ceiling? Does the answer have something to do with air?

The cable of a 3750 lb elevator in the figure below snaps when the elevator is at rest at the first floor so that the bottom is a distance d = 12.0 ft above a cushioning spring whose force constant is k = 10,000 lb/ft. A safety device clamps the guide rails, removing 1000 ft-lb of mechanical...

elevator ?? A 615 N student standing on a scale in an elevator notices that the scale reads 645 N. would the elevator be moving up or down?

If an elevator.. was free falling at its max speed. Would i be able to jump while I am in the elevator?

The Problem: A car is to be hoisted by elevator to the fourth floor of a parking garage, which is 48ft. above the ground. If the elevator can accelerate at 0.6 \frac{ft.}{s^2}, decelerate at 0.3 \frac{ft.}{s^2}, and reach a maximum speed of 8 \frac{ft.}{s}, determine the shortest time to make...

good day all I've no idea how to work this out this is the problem A 5.5-kg object is suspended by a string from the ceiling of an elevator that is accelerating downward at a rate of 2.5m/s^2 What is the tension in the string? i presume tension is the force that's on the string? so i...

An elevator weighs 10000N. What is the tension on the line when the elevator is accelerating upwards at 3 m/s? I don't know how to go about this one. Any help?

8 A boy of mass 65 kg stands on the floor of an elevator. a What is the weight of the boy? b What is the reaction of the floor of the elevator on the boy? The elevator starts to move upwards with an acceleration of 1.0 m s–2. c What is now the reaction of the floor of the elevator on the...

http://www.newscientistspace.com/article/dn8725" Jolly Cool.

A student stands on a bathroom scale in an elevator at rest on the 64th floor of a building. The scale reads 836 N. a) As the elevator moves up, the scale reading increases to 935 N, then decreases back to 836 N. Find the acceleration of the elevator. b) As the elevator approaches the 74th...

A PBS program said that the theory of general relativity holds acceleration and gravity observationally equivalent. (Einstein's space elevator example was given.) Here is a thought experiment based on that mental picture. A "gravity switch" will make the following thought experiment easier to...

Holy crap, a vacuum in-home elevator? http://www.gizmag.com/go/4007/ I WANT THAT! Not really for myself... but to move lots of crap up and downstairs where id normally have to make like 50 trips :)

A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.72 of the person's regular weight. Calculate the acceleration of the elevator, and find the direction of acceleration. I know that the direction of acceleration is...

If carbon nanotubes are great conductors, and if a wire moved through a magnetic field generates electricity, then a space elevator constructed out of carbon nanotubes should be able to generate a lot of electricity. Maybe too much. I think the carbon nanotubes would melt. Indeed, if there...

you are standing on a scale in an elevator. the scale reads 176lb when the elevator is at rest. the elevator begins to accelerate upward at 12ft/s^2. what is the reading of the scale? i converted 176lb to 80kg. i know the sum of all forces equals mass*acceleration but i don't know what...

If a man weights 50kg, but a scale in the elevator says he is 300N, what can you say about the acceleration? Thanks a lot

I know you must get these all of the time but... There is a man standing on a scale in an elevator reading 490N. When the elevator is at rest what does the scale read? I want to say 490 N because the elevator is in equilibrium, but I'm not sure...