Lift Definition and 593 Threads

As a helium balloon increases in altitude, the density of the air inside decreases. However, the density of the air surrounding it (The atmosphere) also decreases with altitude p=p0*exp(-z/z0), where z0 is the scale height of the atmosphere. So does this mean the lift force acting on the...

Can anyone point in the direction of any information on dry lift testing for turboshaft fuel pumps? I need to write a good practices guideline for this and need to find as much info as I can. Thanks.

I came accros this question while reading a bit of Logic and i was wondering what you guys think about. If Zeus can do anything can he make a stone he cannot lift? Hope its not too trivial. thanks

Hi, i have to find a formula for the coefficient of lift that has the angle of attack and wing shape (airfoil shape) in it. Also, where can i find airfoil shapes for different planes? Thanks

A small body is released so that it falls to the floor of a lift moving downwards at a constant velocity. How would the acceleration of the body as observed by someone in the lift compared with that observed by a person stationary with respevt to the lift shaft?

Homework Statement given, diameter and height of pool, depth of water, density of water and gravitational acceleration. g = 9.8 height is 4m 2r = 20m depth of water = 3.5m density =1000kg/m^3 So, I'm supposed to find how much work is needed in joules to lift the water out of the pool...

is the formula below valid to calculate the lift coefficient for a delta wing? Cl=2*L/(rho*v^2*A) L=lift (N) rho= air density v= air velocity A=wing area im doing a subsonic wind tunnel project where I am going to measure the lift for a low aspect ratio delta wing. should i use...

:redface: 1. i need to design an electro magnet that can lift a 1 Kg weight vertically with the minimum cost possible ANYONE GOT ANY IDEAS and i need it to be very presize i mean the measurements thanx

Hi i am new in this forum, and i have a paper on aerodynamics, which is a bit general... Basically the paper is on how to affect lift and drag in automotives... could you help me with this... thanks

Homework Statement balloons are required to lift 20 metric tons. the pressure of helium is 101.325kpa. temp=21.1degcelsius. what should be the diameter of the balloon if it was spherical in shape in order to lift the weight? Homework Equations bouyant force?? The Attempt at...

Hi, I'm currently doing a research study on the effect of the presence of a rear car spoiler on the lift of a vehicle at low speeds As far as my understanding, with an increase in air velocity, there should be an increase in lift on the car. My trials however show that with an increase in air...

1. A T-bar tow is required to pull 89 skiers up a 600 m slope inclined at 15° above horizontal at a speed of 2.5 m/s. The coefficient of kinetic friction is 0.06. Find the motor power required if the mass of the average skier is 65 kg. 2. w=F*d P=F*v 3. I found the...

Work to lift the weight?? A 1000-lb weight is being lifted to a height 10 feet off the ground. It is lifted using a rope which weighs 4lb per foot and which is being pulled up by construction workers standing on a roof 30 feet off the ground. Find the work done to lift the weight?

Hi, I have a question regarding the forces involved in an inclined elevator boat lift. Attached is a diagram of the setup. I was wondering what forces are involved. I know that there is a torque that is exerted on the inclined arm equal to the weight of the boat times the distance of the...

Homework Statement A lift in free fall with Dr. Bhargav inside. In order to save his calculator he throws it up with 1 m/s from 1 meter above the floor of the lift. It reaches the sealing in two seconds. Calculate height of lift. The Attempt at a Solution As the wt in free fall=0...

Homework Statement What is the net upward force on an airplane wing of area 20 m2 if the speed of air flow is 300 m/s across the top and 280 m/s across the bottom. Homework Equations The Attempt at a Solution I have a feeling that this is an easy question, but i just don't know...

I am trying to build my own boat lift that uses plastic tanks submerged to lift the boat when they become filled with air. My problem is that I need to lift about 10,000 lbs and i don't know how large the tanks need to be ( how much water they need to displace ) to lift that amount of weight...

How would a lift accelerating upwards affect the shape of the flame of a candle in it? My instinct says it would flatten it, but I'm not sure how to explain why. Any help?

i was reading on the moller skycar which has multiple wankel rotary engines powering ducted fans for lift, i was wondering if anyone had any information on how many pound of lift one of these engines on a regular ducted fan would have

Need some suggestions... I have a banked airplane at theta degrees, with a radius, and velocity. What is the formula for finding lift force. Fc = Fn sin theta I believe, but that's the only formula I am aware of. Thanks!, -Mike

Hi I've got a question concerning a previous question I've done. A person is holding a toy airplane which flys in the air with a constant radius. is the lift force the same as reaction force? is it equal to the vertical component of the centripetal force and weight force of the airplane?

A 4600 kg helicopter accelerates upward at 2.0 m/s^2. What lift force is exerted by the air on the propellors? I don't know how to do it. Please help :confused:

Hey here is a quick question. I have a question on an assignment that is asking me to define lift in an aircraft (done) and its relationship to the aircraft's centre of mass. I'm unsure how to do that second bit as lift acts through the centre of pressure...not the centre of mass (also known as...

In an TV advertisement, a young man was lifted by an artificial spring water to a hight about 4 m. Supposed the man's weight is 800N, and the sectional area of the spring water is 0.2*0.2 m^2, and using the impuse-momentum theorem, I got a velocity of the spring water of 4m/s. Is this correct?

I have another question maybe someone can help me with. I have attached a drawing of a beam (tube) that is 42" long and weighs 50 lbs. The beam pivots at one end (red dot). If the beam weighs 50 lbs how much force is required to lift the beam to a vertical position if I apply force at a 45...

Is lift essentially created because of higher pressure at the bottom of the wing compared to the top of the wing, causing a postive net upward force? With PA=F And the difference in pressure is created from lower wind or fluid speed at the bottom of the wing compared to the top of it...

Hi guys, I've heard that this topic has been discussed to death before but hopefully not here yet I apologise if it has been. I'm currently in high school we're just into bernoulli's equation and one of the applications is the airfoil. Our textbooks states that the fundamental source of...

the force of lift excerted on an airplane is defined as F = Lc * D * v^2 * A where Lc is the lift coefficient, D is the air density, v velocity, and A the lift area of the wing structure. If i use SI units, the Force is expressed in Newtons. What I'm trying to grasp here, is how does this apply...

emm, i m new member here maybe i m stupid and young enuf to ask these question, but i seriously nid help from u all to explain to me 1st, if we standing on a weighing machine in a lift, when the lift accelerate downward, the reading of W.M. wil decrease?and when accelerate upward the reading...

Hi, i am currently doing a project on these questions. 1)why do we feel heavier when the lift startes to move up? 2) why do we feel normal in the middle? 3) why do we feel lighter when the lifts comes to a stop? although i know that the three laws of Newton is somehow related to...

if an aircraft with a coefficient of lift of 0.05322 is traveling at the velocity of 240 kts at sea level, how much lift is required to fly at level unaccelerated flight if the aircraft weighs 800 lbs? (hint: trick question)

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...

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...

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...

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)...

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...

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...

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...

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...

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...

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...

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?

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...

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..

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...

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...

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...

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...

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...

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...