Lift Definition and 614 Threads

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.

View More On Wikipedia.org
  1. C

    Measuring Lift Curve Slope on a 1/2-Wing vs Full Wing

    If I take an infinitely long, thin wing and measure its lift curve slope I should get 2pi. Now if I take a 1/2-wing and fit 1 end to a plate and test it in a wind tunnel, it should simulate the flow around a full span wing, am I wrong? Therefore measuring lift and working out the CL values...
  2. W

    How Does Bernoulli's Principle Explain Everyday Phenomena?

    Hello, I am a student taking Conceptual Physics in College. We have just completed going over Bernoulli's Principle of lift. Please bear with me on this as it will most likely seem elementary to most of you. Below are several claims that I've heard and that my logical reasoning tells me to be...
  3. M

    Zero Mach number lift coefficient

    I have some aerodynamics homework to finish up, and I am not really sure how to do one part. Question is: What is the corresponding zero Mach number lift coefficient I can't find an equation in my book or anything. Can someone maybe shed some light? My first two questions were to...
  4. W

    Designing a Small Ski Lift: Facts and Assumptions

    I'm planning on building a small ski lift for my kids. It's been 20 years since I've taken a physics class so I'm lucky to remember what gravity is. :blushing: Here's a poor image of the hill. I would like to know the following: A) how much lbs of tension is against the lift wire? B)...
  5. A

    How Can a Hairdryer Power a Machine to Lift 1 kg in a Physics Project?

    Physics project - need help! I am building a physics machine that is supposed to use a hairdryer (Not sure what the Newton force of the hairdryer is) but it lifts 1 kg a certain distance in a certain length of time. You can do it in portions, like .5 kg once and then another .5 again. So far...
  6. E

    Can a Plane Take Off from a Backward-Moving Runway?

    A plane is standing on a runway which is moving the opposite way of the plane.If the plane increases its speed, the runway wil too, but in the opposite direction of the plane.Will the plane manage to lift off? This is what I think:No, the plane will not lift off.Thats because when the plane...
  7. P

    Pressure and lift force on a wing

    An airplane has a mass of 1.60-10^4 kg and each wing has an area of 40.0m^2. During level flight, the pressure on the lower wing surface is 7.00-10^4 Pa. Determine the LIFT FORCE on the plane. Is it sufficient to lift the plane? part is what concerns me: if it is in level flight, the net...
  8. A

    Force must be applied to the small piston to lift the engine?

    In a machine shop, a hydraulic lift is used to raise heavy equipment for repairs. The system has a small piston with a cross-sectional area of 0.057m^2 and a large piston with a cross-sectional area of 0.208m^2. An engine weighing 2900N rests on the large piston. What force must be applied to...
  9. V

    Fluid Mechanics: Hydraulic Lift

    Hi, I have here a problem that I've been working on, and am not sure if I've gone about it correctly. The method I chose seems too simple, and I was wondering if someone could go over the answer that I've found, and let me know if I'm doing this right.The problem: The piston of a hydraulic...
  10. rcgldr

    Debunking the Myth: How Wings Really Generate Lift Without 'Hump' Theory

    One of my pet peaves is how many web sites and books use "hump" theory to explain lift: "the hump on top of a wing makes the air travel further to catch up to the air below and faster moving air has less pressure". For example, older versions of Microsoft Encarta used "hump" theory, until the...
  11. I

    Lift Formula: SI Units & Coefficient of Lift

    About the lift formula i know its "F= Cl/2 P V^2 S" but my questions are what units do you use for each value (still SI?) and is there any formula for finding the caofiscient of lift, if not then how do you find it out?
  12. T

    Designing a Simple Hydraulic Lift for Pascal's Principle Presentation

    I have this project for school and it is all about Pascal's Principle. Well I've decided I would like to make a hydraulic lift to go along with my presentation and just need some help with the design. I figure I can make it out of PVC or Copper tubing, either way I don't mind buying most of...
  13. R

    Maximum weight that helium balloon can lift

    Hi. I have been trying to do this question for about an hour now... A 0.12 kg balloon is filled with helium (density-0.179). If the balloon is a sphere with a radius of 5.2m what is the maximum weight it can lift. I tried using the P=M/V then Fb=pgV...No luck...Help..
  14. T

    What is the lift force exerted by the air on the rotors?

    A 6520 kg helicopter accelerates upward at 0.57 m/s2 while lifting a 1190 kg car. (a) What is the lift force exerted by the air on the rotors? _________ N (b) What is the tension in the cable (ignore its mass) that connects the car to the helicopter? _____N I have no idea how to do...
  15. P

    Lift and Pressure Question ( )

    I also posted this in the homework help, but I may get more help here. This is the problem: We are given either a local velocity or local coefficient of pressure. Using one, the other can be solved. Freestream V is given. Now, if that Cp is the average Cp on the upper surface of a wing...
  16. P

    How Do You Calculate the Coefficient of Lift from Local Cp and Velocity?

    This is the problem: We are given either a local velocity or local coefficient of pressure. Using one, the other can be solved. Freestream V is given. Now, if that Cp is the average Cp on the upper surface of a wing and that upper surface provides 3/4 of the lift, what is the coefficient...
  17. C

    How Do You Design a Safe and Efficient Plasterboard Lift?

    Hi everyone For my college project I am designing a hydraulic telescopic cylinder type plasterboard lift and need help in finding the correct methods/formulas to use in order to design the safe dimensions for the wheel base, the plasterboard platform itself and to determine the weight...
  18. C

    Plasterboard/drywall lift design help

    Hi everyone For my college project I am designing a hydraulic telescopic cylinder type plasterboard lift and need help in finding the correct methods/formulas to use in order to design the safe dimensions for the wheel base, the plasterboard platform itself and to determine the weight...
  19. P

    How Does Taper Ratio Influence Lift on a Trapezoidal Wing?

    OK, here is my problem. I have a trapezoidal wing. Assume it is a simple trapezoid, aka the trailing edge has no taper, only the leading edge does. taper ratio = 0.35 lift required = 2.45 N Wing area = 0.07 m^2 CL = 0.682 Root Chord = 20 cm Tip Chord = 7 cm Span = 26 cm RN = 148000 I am...
  20. Clausius2

    On numerical calculation of Lift Force via Potential Flow

    Imagine: I want to compute numerically a POTENTIAL STEADY and INCOMPRESSIBLE flow over an airfoil. The set up of the problem is: \nabla^2\phi=0 \nabla\phi \cdot \overline{n}\big)_{x=surface}=0 no normal velocity component on the airfoil surface. \nabla \phi=\overline{U_\infty} as...
  21. L

    F = Minimum Force Required to Lift Bicycle Wheel off Ground

    The figure shows a bicycle wheel resting against a small step whose height is h = 0.110 m. The weight and radius of the wheel are W = 29.0 N and r = 0.350 m. A horizontal force F is applied to the axle of the wheel. As the magnitude of F increases, there comes a time when the wheel just begins...
  22. P

    Coefficient of lift for a wing is CL

    OK, so the coefficient of lift for a wing is CL. For an airfoil, it is cl. How do I go from Lift for an airfoil to Lift for the whole wing? Is it just multiplying by the wingspan? Thanks!
  23. P

    Calculating Time to Lift 300kg Piano 10 Meters with 400 Watts Power

    I have a 300 kg piano being lifted at a steady speed from the ground to a hieght of 10 meters and the crane that is doing the lifting is providing 400 watts of power. How much time does it take to get the piano to the top. So far I have Power = work/Time so time is Work/ power , so, work is...
  24. P

    How Much Time Does It Take to Lift a 300 kg Piano 10 Meters?

    I have a 300 kg piano being lifted at a steady speed from the ground to a hieght of 10 meters and the crane that is doing the lifting is providing 400 watts of power. How much time does it take to get the piano to the top. So far I have Power = work/Time so time is Work/ power , so, work is...
  25. M

    Does it make since if it takes 675 food Calories to lift me up 17 ft?

    does it make since if it takes 675 food Calories to lift me up 17 ft look below *IGNORING HORIZONTAL DISTANCE* i got to figure out how much work is done to get myself up from my class to the cafeteria which is 17 ft in vertical hieght PE=mgh my weight is 120 lbs i converted to mass...
  26. D

    Calculate Lift Force of 4510 kg Helicopter Accelerating Upward

    A 4510 kg helicopter accelerates upward at 2.1 m/s^2. What lift force is exerted by the air on the propellers? The answer is in Newtons. If you can give me an equation, that would be great. Thanks
  27. H

    Pressure, force, hydraulic lift problem

    A hydraulic lift has two connected pistons with cross-sectional areas 25 cm2 and 630 cm2. It is filled with oil of density 690 kg/m3. I've found that approx. 63.5 kg of mass must be placed on the small piston to support a car of mass 1600 kg at equal fluid levels. but then it asks...
  28. H

    Pressure/force hydraulic lift problem

    A hydraulic lift has two connected pistons with cross-sectional areas 25 cm2 and 630 cm2. It is filled with oil of density 690 kg/m3. I found that about 63.5 kg of mass must be placed on the small piston to support a car of mass 1600 kg at equal fluid levels. But then it asks... With...
  29. A

    Finding the lift of a propeller

    Is there any formula to find the lift genetated by a helicopter propeller?
  30. M

    More Thoughts on lift generation

    I recently read an article where the author stated that the momentum transferred to the air by a passing wing will eventually strike the earth, even from a high cruise altitude (in other words, out of ground effect) I have a problem with this for the following reasons, feedback would be...
  31. M

    What are the factors that contribute to lift generation in airfoils?

    I have read a number of the forums on lift generation, and I would like to add some comments for feedback. I read the forum describing lift as the centripetal force required to curve the airflow (streamlines), and I must say this makes absolute sense, I myself have always believed that...
  32. S

    Exploring the Effects of Propeller Placement on Wing Lift

    If the propeller is placed in front of wings and since the job of the propeller is to accelerate the airflow, wouldn't it result in faster airflow around the wing resulting in increased lift?
  33. U

    The Lift Problem Puzzle: Why He Walked Up?

    Puzzle: A man leaves for his office and takes the lift from the 60th floor to the ground floor. When he returns back he takes the same lift to the 45th floor and then walks up to the 60th floor. Why? Points to remember: 1. He is not a health freak 2. He does not have any relatives or...
  34. S

    Can a Bird Lift a Container of Mass 10 Tonnes?

    I came across this question while looking around the forums at physlink.com: There are birds of mass 20 tonnes in a van of mass 10 tonnes. The back of the van is closed(no air can go in or come out). If now the birds start flying, will the weight of the van decrease? I ask this question...
  35. F

    Rollercoaster up to the top of a lift.

    As you may have noticed I've got a bit of a rollercoaster theme going. My problem now is i have an 800 kg cart and I need to calculate the work done by bringing it to the top of the rollercoaster. The slope of the lift is 20 degrees and the maximum height is 30 m. From this i calculated the...
  36. M

    Coanda or Bernouli, which describes lift?

    When firing my pulse jet I tried various approaches at increasing its' performance without significantly increasing its' weight. When (while holding a piece of larger diameter pipe with channel locks) introducing a larger diameter than the jet diameter pipe into and partially allowing the...
  37. W

    Calculate Acceleration to Lift: 450N-1000N = 250N

    http://img258.echo.cx/img258/4409/lift3ad.png A painter in a crate hangs alongside a building. When the painter, who weighs 1000 N, pulls on the rope, the force he exerts on the floor of the crate is 450 N. If the crate weighs 250 N, find the acceleration. (ans=1.96 m/s²) Lift...
  38. D

    How do you measure lift in a low-speed wind tunnel?

    Hey, I'm trying to measure the lift/drag of a wing in a low-speed wind tunnel, the only ways i might know are using a load cell or force probs, but have no idea about how to set it all up and my school doesn't have the material. So please, can u give me any way using simple things to measure...
  39. P

    Projectile Motion with Lift and Drag

    I need an equation to solve for the distance traveled of a projectile. The variables that I have are lift coefficient, drag coeficient, launch angle and initial velocity. Could someone please help me find the formula I need. Thank you.
  40. S

    Streamflow and lift for Micro Aerial Vehicles?

    What are the equations used to determine the streamflow and lift for Micro Aerial Vehicles? What are the problems with MAVs?
  41. P

    Energy Required to Lift a Heavy Box

    As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. There is no one around to help, so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. You pull up on the rope to lift the box...
  42. B

    What is the Typical Coefficient of Lift for an Aircraft?

    Hello All... I am just wondering about something. The lift equation is, L= \frac {C_L \rho A V^2} 2 where C_L= coeficient of lift \rho= air density A= area of wingspan V= velocity of the aircraft Does anyone have idea on what the...
  43. X

    Explanation of Bernouilli's principal of lift?

    Does anyone have a diagram and/or explination of Bernouilli's principal of lift?
  44. A

    Lift as a consequence of streamline arguments

    A recently closed thread dealt with the generation of aerodynamic lift, in particular tied to a severe and justified criticism of the "equal transit time"-principle, which often is also called the "Bernoulli effect". However, from what I read, no one showed how streamline arguments can...
  45. R

    Would this force be large enough to lift a 60 kg person?

    A tennis ball may leave the racket of a top player on the serve with a speed of 62.0 m/s. If the ball's mass is 0.0600 kg and it is in contact with the racket for 0.0200 s, what is the average force on the ball? Would this force be large enough to lift a 60 kg person? large enough or not...
  46. U

    Can a Wind Tunnel Bootstrap Itself?

    A school mate of mine was joking when he said you can lift your wind tunnel up if you mount the airfoil to the sides with the high Angle of attack and fast enough airflow. Is this true? If you have say a rectangular glass wind tunnel (fish aquarium shape) and put a large size wing and fast...
  47. H

    Calculating Force Required to Lift Box at 8 m/s^2

    A box weighs 2000N and is accelerated uniformly over a horizontal surface at a rate of 8 m/s^2. The opposing force of friction between the box and the surface is 27.4 .. How much force would be required to lift the box upward with an acceleration of 8 m/s^2? I know that the answer is...
  48. S

    Calculating Work to Lift Kite String from Ground: A Puzzle

    Hi - Here's the entire problem to avoid confusion >< "A kite is flying at a height of 500 ft and at a horizontal distance of 100 ft from the stringholder on the ground. The kite string weighs 1/16 oz/ft and is hanging in the shape of the parabola y=(x^2)/20 that joins the stringholder at...
  49. P

    Calculating Current Needed to Lift a Cross Piece in a Horizontal Magnetic Field

    I been having trouble lately with my phyiscs HW probs. Here is only that ti'm confused on: Three wires are connected to form a vertical H. The cross piece, mass 0.050 kg and length 0.10m , can slide up and down the vertical wires without friction. The device is placed in a horizontal field...
  50. B

    How much time does it take to lift the piano?

    Hello, I thought I knew how to solve for this problem but alas I was wrong. I'm hoping someone will be able to point me in the right direction. Here's the problem: A 1.40x10^2 kg piano is being lifted at a steady speed from ground level straight up to an apartment 18.0m above the ground...
Back
Top