Lift Definition and 593 Threads

I've always been told that systems that involve a heat pump need to be designed for a delta T of about 10C, not the more usual 20C, apparently because the pump can't lift the temperature more than this. Is this correct, and why is this so?

Hi all, I have quite a perfect understanding of hydraulic lift, yet there is one huge problem that is contradicting my understanding. for a hydraulic lift where you push on on side of diameter d1 piston, and the object on a piston of diameter d2, you get the equation: F1/A1 = F2/A2...

Homework Statement A crane contains a hollow drum of mass 150kg and radius 0.8m that is driven by an engine to wind up a cable. The cable passes over a solid cylindrical 30kg pulley 0.3m in radius to lift a 2000N weight. How much torque must the engine apply to the drum to lift the weight...

Hi, I need to make changes to an existing design of a model radio controlled aircraft to increase its lift to carry more payload. Pls confirm my ideas and any suggesstions would be really appreciated. Using wingtips to reduce induced drag and increase lift. Will a Dihedral affect lift in...

Homework Statement Hey, guys. I have this guy trying to lift this cylinder pass the step with minimum force and so is the question, what's the minimum power that he needs to use and at what angle (alpha)? I also added the solution. The thing I don't understand is, why when the momentum of...

1.A man has a hydraulic jack to lift his car. If the smaller piston has a diameter of .75 cm, and the larger piston a diameter of 6.0 cm, how much force will the man have to exert to lift one corner of the car, weighing 700 lb?

Homework Statement http://img186.imageshack.us/my.php?image=gdgdfgta2.jpg the question is on the above link (PART B() Homework Equations deltaF=pg(A1+A2)d2 The Attempt at a Solution deltaF=pg(A1+A2)d2 i used that formula and found that the distance was 0.35m

Homework Statement A chain hangs verticaly from a building. The chain is 30 ft long and is 5 lb/ft3, how much work is needed ot lift the bottom of the chain to the top.Homework Equations If you put the axis where the chain is hanging your limits would be 0 and -30The Attempt at a Solution So I...

Creating lift equation---NEED HELP! For a course I am taking, I need to determine a lift equation based on some variables. Propose an equation for lift as a function of your three parameters. That is, if L=lift, A=Area, ρ=air density, and v=velocity, determine L(A, ρ, v). I am just so...

Homework Statement the gondola ski lift at kystone, Corolrado is 2830m long. On avg, the ski lift rises 14.6 degree above the horizontal. How high is the top of the ski lift relative to the base. Homework Equations tan * = ha/h The Attempt at a Solution i just...

I was thinking about Bernouli's principle, which shows how to get lift by creating a difference in air pressure above and below the wings of an aircraft, and became curious as to whether a difference in pressure arrived at by other means might also result in lift. Specifically, if air were...

Buoyant Lift Creates Useful Energy? I work at a manufacturing plant. One by product of this plant is the issuance of 2000 cfm (cubic feet per minute) of clean air. It is determined that this air could be released from as small as a 3 inch pipe with no adverse harm to the manufacturing...

Im trying to calculate energy of the turbines to lift an airplane , by this way, calculating potential energy necessary to lift mass of the plane to an height of, let's say, 2000 meters , ,supose it spend 1 minute in reach this altitude, it gives me a result of the order of 1 megawatts of...

just out of curiosity if i wanted to lift something about 150lbs out of the air with a jet engine or rocket, to hold it against the Earth's gravitational pull 9.8m/s how much energy/power would i need? would it also depend on how heavy the engine is? and what other factors are there in this problem?

Hi, I was just wondering why the air going over a wing travels faster than the air going underneath? My teacher once said "because it has farther to travel" and I just accepted that at the time, but thinking about it now i don't really see why two adjacent air molecules that part company at the...

hi, i have this problem that i am trying to figure out, but seems i need some help..:) ii have attached an image and an animation to clearly explain my problem. what i am trying to understand is will the green base with its 1000kg lift force be able to lift the pole with the red dot (950kg)...

Lift ! (airplanes) Hello, I am writing a research paper about the lift generated by the wings of an airplane. It is about the extent to which the Bernoulli effect and Newton's laws each contribute to creating lift. I planned on calculating the actual value of the lift generated by each...

Hello, this question is about lift in fixed wing flight (airplanes). Is it possible to calculate separately the lift generated by: - Newton's laws (wings deflecting air particles) - Bernoulli effect (difference in air pressure above and below the wings caused by the shape of the...

Okay, so I'm stuck on the last part of the problem : A hydraulic lift has two connected pistons with cross-sectional areas 15 cm2 and 430 cm2. It is filled with oil of density 620 kg/m3. -------------------------------------------------------------------------------- a) What mass must...

Anyone know how you get the formula F = rho*g*(A1+A2)d2 which is used to find the additional force needed to be applied to a piston to lift a car a distance of d2? Thanks.

I'm working on a project with several others to create a flying device much like a blimp, but smaller and more agile. Our method of life is eighther a light gas like helium or preferablly, a Vacuum system that ajusts the % of vacuum inside a set space to provide lift and control decent. The...

[SOLVED] Lift, reading on the scale Homework Statement Mandy stands on a weighing scale inside a lift (elevator) that accelerates vertically upwards. The forces on Mandy are her weight W and the reaction force from the scale R. The reading of the scale is A. R + W. B. W. C. R. D. R – W. The...

Question: On one side of a wheel there is 50 lbs of weight, if the wheel is released the weights would rotate with the wheel until the weights where at the bottom and stop. Let's say this wheel has a shaft in the middle of the wheel that turns as the wheel does, if you put weights on one side...

Ok so I just read this statement as part of an explanation of list using Newton's 3rd law "The amazing thing about wings is that because they are flying through air which is a fluid, the top of the wing deflects air down as well as the bottom of the wing." What I don't understand is how...

A box of mass 6.2KG stands on the floor of a lift which is moving with an upward acceleration of 0.2ms^-2. A horizontal force of magnitude 16N acts on the box. There is no horizontal movement of the box. Find the magnitude and direction of the resultant of the forces, normal and frictional...

Homework Statement A heavy conductor (mass m, length [FONT="Courier New"]l, resistance R) is suspended by two springs each with spring constant k, and connected to a battery with electric potential V as shown in the figure. A magnetic field B is now imposed. The acceleration of gravity is 9.8...

Homework Statement A hydraulic lift has two connected pistons with cross-sectional areas 25 cm2 and 700 cm2. It is filled with oil of density 570 kg/m3. a) What mass must be placed on the small piston to support a car of mass 1300 kg at equal fluid levels? (answer: 46.4kg) b) With the...

I've been trying to conceptualise accurately the lift forces upon an aircraft in physics terms, for a simulator flight manual I've been working on. What I've got from some rudimentary flight training is that low pressure above the wing rather than high pressure below it causes lift, obviously...

i'm having difficulty with part C of this problem. A hydraulic lift has two connected pistons with cross-sectional areas 25 cm2 and 430 cm2. It is filled with oil of density 500 kg/m3. a) What mass must be placed on the small piston to support a car of mass 1300 kg at equal fluid levels...

I know about Bernoulli's principle and that a difference of pressure below and above a wing create lift, but I cannot find anywhere a formula or any information on how to find the amount of lift given the surface area of the wing and the difference in pressure as a percentage of atmospheric...

Hello, I harvest lake weeds and I'm looking for an easier way to remove the aquatic weeds from the water after they are cut. A couple of quick ideas were to use an older pontoon as a way to transport the weeds out of the lake. 1) Thought about some type of hydrolic lift table that could...

An old oaken bucket of mass 6.75 kg hangs in a well at the end of a rope. The rope passes over a frictionless pulley at the top of the well, and you pull horizontally on the end of the rope to raise the bucket slowly a distance of 4.00 m. So far, I have: F = force exerted by me s =...

[SOLVED] mass of gas required to lift another mass Homework Statement A balloon contains gas of density G and is to lift a mass M, including the balloon but not the gas. Show that the minimum mass of gas required is m=(MG)/(A-G) where A is the atmospheric density. Homework Equations...

Homework Statement A 12,000 N car is raised using a hydraulic lift, which consist of a U - tube with arm of unequal areas, filled with oil with a density of 800 kg/m^3 and capped at both ends with tight-fitting pistons. The wider arm of the U tube had a radius of 18. cm and the narrower arm...

I am interested in this Hobby. I have seen several experiments and it looks pretty easy to do. I am wondering what exactly lifts this? Is it Ions or ?? They had done a test in a vacuum chamber and it was still working, are ions present in a vacume? If it's not ions, then what makes the...

Homework Statement A hydraulic lift has two connected pistons with cross-sectional areas 5 cm2 and 550 cm2. It is filled with oil of density 520 kg/m3. a) What mass must be placed on the small piston to support a car of mass 1500 kg at equal fluid levels? this was no prob. =13.61...

Homework Statement A hydraulic lift has two connected pistons with cross-sectional areas 5 cm^2 and 550 cm^2. It is filled with oil of density 520 kg/m3. a) What mass must be placed on the small piston to support a car of mass 1500 kg at equal fluid levels? Homework Equations...

I think this is a pretty simple question but I can't seem to figure it out: If there is a 90,000 kg building (20 m deep, 10 m long, and 10 m wide) on the surface of Saturns moon, Titan, how fast does wind have to blow over the top to have the structure become "weightless" (the air below the...

When an air passes over the wingtip of the airfoil, the upwash created at the leading edge 'reduces' the Angle of Attack, thus reducing lift. So why does this affect increase induced drag. The way I understand it, the greater the AoA (more lift), the more induced drag that is generated. Help...

I've just finished the practical part of an investigation into lift and angle of attack. I also took airspeed readings over the top and bottom of the wing at the leading and trailing edges. What I'm having trouble with is grasping how lift is generated. I understand the underlying principles...

Homework Statement How much tension must a rope withstand if it is used to accelerate a 1400 kg car vertically upward at 0.50 m/s2? Homework Equations Fg=mg F=ma The Attempt at a Solution So far i know Fg=13720 and the Fnet is 700 so I'm not sure but do i subtract 700 from 13720?

Homework Statement Under standard conditions, the density of air is 1.293 kg/m3 and that of helium is 0.178 kg/m3. A spherical helium balloon lifts a basket plus cargo of mass 269.0 kg. What must be the minimum diameter of the spherical balloon? Homework Equations p = F/A The...

Ok, propably everyone here knows that IN THEORY it is possible for a human to fly. This question has been bugging me a lot and I know it can be solved using some kind of aerial physics (Dont know the term :D). Therefore my question is: How fast must 75 kilograms weighing human wave his hands...

Homework Statement A rod is being used as a lever as shown. The fulcrum is 1.2 m from the load and 2.4 m from the applied force. If the load has a mass of 11.6 kg, what force must be applied to lift the load? ____ N Homework Equations ? The Attempt at a Solution When doing...

I understand how an ordinary wing works but I cannot find anything on how a delta wing works, the only thing I know is that it creates vortices on the upper wing surface, but how do these vortices create lift?

Homework Statement Hey everyone, this problem has been bugging me for days now, and no matter how many times I've attempted it, I feel like its going wrong. http://img258.echo.cx/img258/4409/lift3ad.png The buillder has a mass of 75kg and the cradle has a mass of 35kg. The builder...

Is More work is done to lift a 4.00-kg object a distance of 1.00 m at a constant velocity than to push a 1.00-kg block a distance of 1.00 m with a force of 39.2 N? I can find the work done in the 2nd case using W=fd= 39.2 J.

Homework Statement A 5400 kg helicopter accelerates upward at 2.17 m/s2. The acceleration due to gravity is 9.8 m/s2. What life force is exerted by the air on the propellers? Answer in N. Homework Equations Fnet=ma The Attempt at a Solution I am making the acceleration positive...

Anyone know how long a typical let's say news helicopter can last in the air given how much fuel it holds? I am not sure but I heard a news helicopter or a police helicopter probably won't last more than 3 hours in the air. Some military transport helicopters can only do about 2 and attack...

Homework Statement 1) Consider the hydraulic lift which has a smaller piston of area A1 and a larger piston area A2. Initially the two pistons are not moving. Show that in order to raise the larger piston by a distance d2, it is necessary to apply a force △F = ρg(A1 + A2)d2 on a smaller...