What is Lift: Definition and 613 Discussions

A surface lift is a means of cable transport for snow sports in which skiers and snowboarders remain on the ground as they are pulled uphill. While they were once prevalent, they have been overtaken in popularity by higher-capacity and higher-comfort aerial lifts, such as chairlifts and gondola lifts. Today, surface lifts are most often found on beginner slopes, small ski areas, and peripheral slopes. They are also often utilized to access glacier ski slopes because their supports can be anchored in glacier ice due to the lower forces and realigned due to glacier movement.
Surface lifts have some disadvantages compared to aerial lifts: they require more passenger skill and may be difficult for some beginners and children; sometimes they lack a suitable route back to the piste; the snow surface must be continuous; they can get in the way of skiable terrain; they are relatively slow in speed and have lower capacity.
Surface lifts have some advantages over aerial lifts: they can be exited before the lift reaches the top, they can often continue operating in wind conditions too strong for a chairlift; they require less maintenance and are much less expensive to install and operate.

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  1. N

    Acceleration of Space Shuttle at Lift Off

    Homework Statement The mass of a space shuttle is approximately 2.0 x10^6 kg. If the thrust provides a force of 1.2 x 10^7 N, what is the acceleration of the space shuttle at lift off? 6.0 m/s2 0.06 m/s2 1.67 m/s2 0.167 m/s2 Homework Equations Resultant force = thrust – weight Acceleration =...
  2. C

    What is the Lift Coefficient of a Basketball?

    How can I find an equation to calculate the lift coefficient on a basketball at different launch velocities? I looked at different papers explaining the physics of basketball throws but all i could find was an equation for the drag coefficient: -mv +1/2 ρ A Cd v^2 = mv
  3. Gbl911

    Center of Lift vs. Center of Thrust

    I have been thinking about the CoL and CoT on rockets. I came to the conclusion that they are in the exact same spot on the rocket since your thrust and lift come from the same thing in the same place, the engine. I read some forums on other websites but didn't get a clear answer. It would be...
  4. B

    Energy to lift a mass, voltage, amps, time, distance confuse

    Homework Statement A student investigates the efficiency of a small electric motor. He uses a motor to lift it a mass through a constant distance of 1 m. He times how long it takes to lift the masses and makes a record of the potential difference and the current of the motor. In the book that...
  5. MdAsher

    Understanding Fluid Dynamics of a Flying Frisbee

    Hi All, I'm hoping to work on deriving the governing fluid flow equations for a frisbee in flight theoretically and then to test it on a wind tunnel, and compare results. If u could please help on how do i apply/derive the necessary equations. Respectful Regards
  6. Necronox

    How can the lift produced by animal wings be calculated?

    Firstly, I'm new to these forums, and I'm not sure what the prefixe in creating this thread is supposed to be... (i'm assuming it is to judge to question's level)? saw some threads without prefixes but i can't post one without... maybe i missed a stickied thread or a readme? Alright, so, first...
  7. J

    Understanding the Power of Elevator Lift Systems

    Homework Statement Homework Equations P=Fv The Attempt at a Solution Since the elevator is rising at a steady speed, a=0, thus, the tension on the string equals to the weight of the elevator. I chose C as I thought just for the elevator case, it would be m1gv, but how does m2 affects the...
  8. Neon

    Is there just one correct way to calculate wing lift?

    Wings generate lift because of the curved shape of the top wing air flow faster over the top and sucked up the plane. This would be bad for a fighter jet flying upside down. Wright brothers plane wings are flat so the wing must be deflected down. So curved wings are just aerodynamic. Soo which...
  9. Y

    Discovering Lift Force in Case 2

    We all know the lift force in case 1, what about case 2 ?
  10. T

    Wing Lift Energy: Exploring Forces & Thermodynamics

    I would much appreciate any critique to this line of thinking. Draw a circle around the airplane to see it as a free body diagram. The airplane engine provides horizontal force to move the plane. Force (F=ma) is a vector quantity with a horizontal direction. The wing lift is a force in the...
  11. A

    Determining Tension & Lift Force for Helicopter & Truck

    Homework Statement A 15000-kg helicopter is lowering a 4000-kg truck by a cable of fixed length. The truck, helicopter, and cable are descending at 15.0 m/s and must be slowed to 5.00 m/s in the next 50.0 m of descent to prevent damaging the truck. Assume a constant rate of slowing. Determine...
  12. toforfiltum

    Min force to lever to lift weight

    Homework Statement Homework Equations Concept of couple? The Attempt at a Solution First, I calculated the couple about disc, though I'm not sure if I can use this approach. Since 900 N is pulling the string of pulley downwards, I take the couple about disc as 900 x 0.4, which gives me 360...
  13. Mr Davis 97

    Work done to lift an object

    I am a little confused about the work do the to lift an object. I know that in lifting an object a net force must be applied in order to increase its velocity, but when the object stops, gravity applies an equal but opposite force, which means that in lifting an object no net work on the object...
  14. Robin04

    Which is the correct explanation for lift?

    Hi, I read several approach to the explanation of aerodynamic lift. Bernoulli, Newton, Kutta-Joukowski. I found a topic about discussing Bernoulli and Newton, and the conclusion was that they are both valid individually. But what about the Kuttaa-Joukowski theorem? And are these approaches all...
  15. MattRob

    Exploring Power Needed to Lift Mass

    I'm a little afraid to ask something that should be such a basic question, yet there seems to be an enormous discrepency in-between theory and reality, here. In many, many problems I've worked with "find the work to lift X", you simply take the change in potential energy. When lifting Mass m by...
  16. R

    Need to build a Large Lift Electromagnet

    Hi Everyone, not sure why it is so difficult to find any info on how to build a simple electromagnet with diagrams or plans... but it is! I need to lift sheet plate... thousand poinds or more... something like a 2 car battery design electromagnet for lifting... Please, Please, don't tell me I...
  17. O

    How to calculate weight and force required to lift a flap?

    Hi all,I would like to know how to calculate the force required to lift a flap (or drawbridge if you proffer) of known weight that is on a pivot and where the pull chain (let’s say it’s a chain) connects to the flap at a known distance from the pivot.I’d also like to be able to calculate the...
  18. amorphos_b

    What would it take for this to lift a man?

    What would it take for this to lift a man? Hi, as an inventor i am interested to know what it would take to make one of these ideas lift someone into the air? Let's imagine that it is made of graphene covered carbonado mesh frame, such that it is very light. As for power, let's use a rotory...
  19. R

    How much pressure needed for pneumatic cylinders to lift?

    Hello, I work for a company specialized in building van bodies. The problem is our engineer left and I know nothing about pneumatics. The customer's requirement is to be able to raise and lower the roof by up to 1 m. The box bodies are 7-8 meters long, so I think 6-8 pneumatic cylinders will...
  20. T

    Lift relative velocity question.

    Homework Statement From a lift moving upward with a uniform acceleration 'a', a man throws a ball vertically upward with a velocity v relative to the lift.The ball comes back to the man after a time 't' Show that a+g = 2v/t Homework Equations s=ut+1/2gt2 The Attempt at a Solution I know this...
  21. C

    Why Do Ski Lift Pylons Lean? - Colin's Physics Query

    I am in Austria on a walking holiday, Why are the pylons on ski lift's not vertical? I only have A level physics but surely centre of gravity and gravitational force must put tremendous pressure on the back of the pylon, as it will naturally want to lean fwd. My friend says this is just good...
  22. H

    Help with troubleshooting a scissor lift

    I http://www.pentalift.com/lift-tables/scissor-lifts&multi-stage.php. It works fine, when a single person is in the lift, but when 2 people of average weight are in the lift it will not go up properly. We haven’t exceeded the rated maximum capacity of the lift platform. It seems like it does not...
  23. marciokoko

    How to calculate the force needed to get out of bed?

    I know from physics 101 that f = ma. And if I want to lift an object straight up i have to multiply its mass times gravity (acceleration) and I get the force I need to require to overcome it. But what about lifting your body out of bed? Just the part where you physically get up from the lying...
  24. B

    Fe needed to lift up mass of size m

    opposites magnetic fields repel each others. How big of an magnetic would I need to lift mass ( 5g) 3 centimetre in the air. F = MA A = 9.81 m/s^2 M = mass of the object ( 5 g) F = 49.05 F = I L x B 49.05 = IL X B I = 3000 mA ( from a AA battery) µ = 4π E-7 T m/A Bsol = µ N/L I F = IL X...
  25. C

    Valve lift & variable air flowrate in compressed air

    How we can incorporate valve lift and variable flow rate in compressed air engine Mechanical power = air power torque * angular velocity = pressure * flow rate
  26. Y

    How to calculte Kinetic Energy of Scissor Lift system

    Hi, here i need to calculate the tilt angle of the scissor lift. I had done some reviews for designing a scissor lifter, some source state that, tip-over will happen only when the kinetic energy of the system is less than the Potential energy after impact. Hence, i was trying to use this...
  27. bananabandana

    Does Acceleration Affect the Stability of an Atwood Machine in an Elevator?

    Homework Statement Please see attached for diagram. We know that the elevator arm is horizontal when the lift is stationary, with ## M_{1}=\frac{4M_{2}M_{3}}{(M_{2}+M_{3})}## It wants us to find out if this is still the case when the lift is accelerated upwards at a constant velocity ##g##...
  28. Q

    How much effort to lift a human being?

    What size propeller is required to lift a 180 lb person 30ft into the air consistently? Also, how powerful would the motor have to be to lift itself, the propeller, and person?
  29. M

    Understanding Airplane Lift: Exploring the Mechanics of Flight

    I'm confused about how an airplane generates lift. If I'm correct the wing of the plane is bent so air can flow over the top of the wing faster than the bottom of the wing, the faster fluids somehow apply less pressure resulting in a net upward force. Why though does a bent wing allow air to...
  30. P

    Simple Pendulum in Free Fall: Surprising Motion and Video Evidence

    Homework Statement This is a 'random discussion' that I had today with a student; it is not out of a textbook, nor does the solution carry any weight at all (pls excuse pun).[/B] A simple pendulum is happily swinging back and forth attached to a pin in the wall of the lift, where the pin is...
  31. Spock

    Can centripetal/centrifugal force raise itself

    So my question is, if a laithwaite engine (my attached photo) spins fast enough, will it be able to lift off the ground? And if yes, what's the maths to calculate the speed needed to make it lift?
  32. T

    Angle to lift a body off the surface

    Homework Statement A rectangular box is being pulled by a rope with a force T on a horizontal surface, with a friction coefficient μ. What is the minimum angle α at which it will lift of the surface? See attached image. Homework Equations \begin{equation*} \tau = rF\sin\alpha \end{equation*}...
  33. H

    Work done to lift a mass of water

    Homework Statement A pump is required to lift 800 kg of water (about 210 gallons) per minute from a well 14.0 m deep and eject it with a speed of 18 m/s (a) How much work is done per minute in lifting the water? (b) How much work is done in giving the water the kinetic energy it has when...
  34. C

    Calculate force to lift piston from a given closing pressure

    I am trying to calculate the force required to close the valve on an annular bop. A rubber ring (called a packing unit) closes around the pipe when a force is applied from underneath, as shown here. The actual valve has the hydraulic fluid coming into a chamber that goes the around the outside...
  35. mootz

    Horsepower needed to lift 600 lb load, w/8 motors

    Good day Geniuses. im building a drone prototype for an agricultural project. approx. weight will be 600 lbs, using my own 8 rotor design. trying to determine rotor size and motor power required to fly such a device at 30 feet. would also be interested to determine an approximate wind speed...
  36. leviterande

    Calculate Lift from a full-blown-circulation airfoil?

    Hello everyone! I am interested in roughly calculating the lift from an airfoil that has air circulating around its full circumference, (can be done by a treadmill skin but probably best done in practice by blowing air from slots around the entire circumference as seen in Fig.1) As...
  37. A

    4 in lift mechanism using a continuous servo?

    Hi, I need to design a lift mechanism that is powered by a small continuous servo. It needs to lift a plate up at least 4 inches, and be totally powered by this servo...
  38. V

    Design a 1000Kg Hydraulic Scissors Lift

    Hello guys I want to fabricate hydraulically operated scissors lift. I preformed calculations & fabricated same but unfortunately it didn't work. Can anybody help me out to design it again. Required specifications are Maximum load: 1000Kg Open height: 1500mm Closed height: less than 375 mm...
  39. P

    Drag and Lift Sensors for a Subsonic Wind Tunnel

    Hey everyone, I'm a student working on building a wind tunnel with some classmates. I'm in charge of figuring out the drag and lift force sensors. I'm currently looking these two components: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2128260_-1...
  40. stephenranger

    How Do We Determine the Type of Motion in a Crane Lifting Scenario?

    Homework Statement A crane lifts a load of 3000 kg to a height of 8.5 meters in 15 seconds. Calculate the lift work? Homework EquationsThe Attempt at a Solution This is a very simple problem but the thing is its unclear data. The given data does not clarify whether or not this is an...
  41. O

    Calculating lift force of a motorised hovercraft

    Hello, I need help regarding calculating the lift force for a hovercraft. I found an equations online on thrust propulsion. Equation → T= π/4 x D^2 x (v + Δv/2) x ρ x Δv D- diameter of propeller v- velocity of incoming flow Δv- additional velocity, accelerated by propeller ρ- density of air...
  42. D.Man Hazarika

    Kinematics problem -- A lift ascends from rest with uniform acceleration

    Homework Statement A lift ascends from rest with uniform acceleration of 4m/s², then it moves with uniform velocity and finally comes to rest with uniform retardation of 4m/s². If the total distance covered during ascending by the lift is 28m and the total time for ascending 8s respectively...
  43. M

    Lift capacity of a spring loaded arm

    Hello all, Yet another problem on engineering mechanics. This time I have a spring loaded; counterpoised arm: Something like this- http://www.akwmedical.com/files/imagecache/cart/SK2323_1.jpg http://t3.gstatic.com/images?q=tbn:ANd9GcTUCvnSKhKEbs4uNiOLg2TGU3p0quUrSp8Uh4QXqt5m4eIEf6_ISA What it...
  44. I

    Does the shape of a car produce lift or downforce?

    I have a few questions related to downforce in cars. Please forgive any fundamental misunderstanding of aerodynamics. Does the shape of a car, say a Volkswagen Golf, driving on a road produce lift or downforce? Is the Coanda Effect at play there? How does the height of the car above the ground...
  45. Paradox101

    How Bees Fly: Exploring the Physics Behind Their Flight

    we all have heard about this conundrum,about the bees can't fly because of the whole small surface area of the wings and greater weight than the lift achieved thing.However,there were some articles that I read that this question had been solved, that bees don't flap their wings up and down, they...
  46. S

    Can repulsing magnets create lift?

    Suppose there are 2 sets of magnets housed inside a box.One set can move vertically and the other set moves horizontally.Now if enough repulsion is created between the vertical set's magnets the top magnet will touch the box's body and try to go out but can't.So if I keep the repulsion going...
  47. Paradox101

    Determining the coefficient of lift

    Been working on a new way of determining the lift coefficient besides the thin airfoil theory,and I don't know if there is already such a method or if I'm wrong.Plz Help.We know, L=CL×1/2ρv^2A Now,as lift is a force,then it should be as L=mμ, where μ is the "upwards acceleration". So...
  48. B

    Can I convert a eletric logg splitter in to a dump lift

    Can I convert an electric log spliter and use the hydrolic to create a dump lift? Using my truck and its 12 volt battery
  49. D

    Understanding Lift & Wings: Upscaling Data for Real Planes

    Hi guys, I'm working on a project for school and I have measured the influence of the angle of attack, the wingspan and the speed of the air on the lift force the wing is producing. Now I have the question what these data say about real wings from planes. I've already red it has something to do...
  50. S

    Making ancient time water wheel to lift water

    I have one project of developing setup to lift heavy water at some height. A setup that take less energy as compare to traditional water pumps. I was searching on net and I found giant "water wheels" of ancient times to lift water. Like this one http://en.wikipedia.org/wiki/Norias_of_Hama Is...
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