Drag Definition and 713 Threads

Hi, I am a Senior in High school, looking for some help with a couple of questions that deal with both physics and mathematics. I was given a sheet with 4 scenarios on it, I chose a box falling from a height of 5 meters. The information is shown below: Object mass: 20 grams Dimensions of...

Hey guys, I am working on deriving some equations of motion for an object with air drag. I am using this site to help me: http://www.grc.nasa.gov/WWW/K-12/airplane/flteqs.html Here is my problem, at the bottom of that page they have this equation for horizontal velocity: 1. u =...

Hey, I am trying to calculate the drag force on netting at supersonic speeds. currently I have been using the equation: F = 1/2 (ρ V² Cd A) I am having trouble applying it to netting due to the drag coefficiant, since i cannot find one for netting. Also all the examples I have seen for...

Ok so i have looked and looked for a simple way to under stand how to find drag using the coefficient of drag. the formula i found is off of NASA website and it reads Drag = Coefficient * [ (Density * Velocity ^2)* .5 ] * reference area here is my question what units do i use. When i...

I have a general question concerning the affect of surface treatments or imperfections in the painted surface of the vehicle in relationship to the Drag Coefficient for an automobile. I own a 2006 Hyundai Sonata which has a drag coefficient of 0.32. Over the last six months I have noticed a...

Homework Statement Find an equation describing a body in free-fall in air. This is not really homework. I'm in a differential equations class write now, and I have fun finding real world applications for such things. Homework Equations m\frac{d^{2}y}{dt^{2}} = B\frac{dy}{dt}-mg The Attempt...

I am trying to calculate an acceleratin in a racing (drag)application. I am an engineer at a medical implant manufacturing company so i know a bit about calulations but it has been a while for most (computers,,) Here is the scenario, we race from 150' to 300'. the quickest time determines the...

[SOLVED] very simple drag question Homework Statement A ping pong ball of mass m is thrown downward at twice it's terminal speed. What is its magnitude of acceleration immediately after release in terms of m and any other physical or mathematical constants? Homework Equations This was...

i'm not even sure where to get started with this one because the thorton and marion classical dynamics book is really awful. BEGIN PROBLEM Suppose a baseball, which has a mass of 150 g and a diameter D of 7 cm is released from rest. For a sphere in air, the dynamic drag is F_d=.25 D^2 V^2...

An object is coasting on the horizontal axis, in the positive direction and is subject to a drag force f = -bv - cv^{2}. Write down Newton's 2nd Law and solve for v using separation of variables. So first I wrote out Newton's law as: F= m(dv/dt) = -bv - cv^{2} Solving the integral: dt =...

Homework Statement You have to find the value of k in the drag equation; Fdrag = k*v^2 It is for a car driving. The motors maximal effect is P = 60W, and it uses this, when the car drives 120 km/h or above. Previously, I have calculated that between 30 km/h and 120 km/h, the resulting...

I'd heard this was a relatively newer discovery -- that a blunt-body object traveling through a gas experiences a reduction in drag if that same gas is turned into plasma. I'm haven't read exactly why this occurs, but I'd presume that a gaseous fluid medium becomes easier to pass through if...

First, let me introduce myself. I am new to these forums, but not new to sharing ideas that cause argument. If you think anything I say is wrong, please speak up. The reason I joined was because of this outrageous 2+ year old thread: https://www.physicsforums.com/showthread.php?t=70227 The...

[SOLVED] Aeordynamics, drag, wind resistance - table with Cw values for objects Hello I am not using the standard template as this is a minor question in relation to my assignment, and not the actual questions from the assignment itself. I am calculating the curve of a projectile fired at...

Homework Statement A .63 kg ball is thrown up with an initial speed of 14 m/s and reaches a maximum height of 8.1m. How much energy is dissipated by the air drag acting on the ball during the ascent? Homework Equations KE= 1/2MV^2 The Attempt at a Solution I'm not very good at...

I have a problem in my D.E. class that is driving me nuts. Two drivers, A and B are in a race. Beginning from a standing start they both proceed at a constant acceleration. Driver A covers the last 1/4 of the distance in 3 seconds. Driver B covers the last 1/3 of the distance in 4 seconds...

Homework Statement I am unable to calculate air drag for a projectiles lab I am doing. It involves shooting elastic bands and measuring the distance they travel and compare it to the theoretical distance(with and without friction). It takes 0.45 seconds for the elastic band to fall and...

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...

The problem is to give a projectile an initial velocity such that it lands a certain height and distance away (2D system, only x and y dimensions). The forces to account for are gravity and air drag. The knowns are x is target horizontal distance to travel y is target height to travel g...

Homework Statement A 710 kg car drives at a constant speed of 23 m/s. It is subject to a drag force of 500N. What power is required from the car’s engine to drive the car a. on a level ground? b. up a hill with a slope of 2.0 0? Homework Equations P=Fv The Attempt at a...

Hi Does anyone know the drag coefficient of a missile. Would a missile have a lower drag coefficient then a torpedo? Thanks all

Hi, I have been trying to understand the formula for the drag of an object vs the depth of the object in Water. The variables are Velocity, Mass, Weight. Velocity being in Miles per Hour. Mass taken from the cross section of the weight as it moves through the water and the mass of the line used...

Homework Statement A projectile with mass m is fired upward with an initial speed v0. If the air drag varies with the square of speed F(v)=-kmv2 show that the projectile reaches a height of h=1/2k*ln[1+(kv0^2/g)] Homework Equations F0+F(v) =...

Okay, I've been working on designing a custom mold cut for a 410-gauge shotgun slug and need some help with the principle of "Drag Stabilization". Many shotguns are smooth bores and thus shotgun slugs in order to dependably fly straight must have a drag-stabilized design. They can not depend...

Homework Statement Its a project where I have to create a scenario in which a dragster (Car A) has the highest top speed but loses the race(to Car B) That is all that is given to me, although some random things such as Apocalypses or random explosions are obviously not permitted...

Homework Statement An object dragged through an unknown fluid experiences a force opposite to that of its initial velocity (Vi) that is equal to -k(v^1/2). find the equation that models its instantaneous velocity Fn = Force Net Ff = Frictional force Vi = Initial Velocity V =...

my first post but i had to get this out before i explode! this has been bugging me to hell on this other forum i visit. there are a bunch of people insisting on "negative drag" is there such a thing? from what i understand drag is a force acting on an object moving through a fluid. and...

Homework Statement A baseball is thrown straight up. The drag force is proportional to v^{2}. In terms of g, what is the ball's acceleration when its speed is half its terminal speed and a) it is moving up? b) it is moving back down? Homework Equations \sum F=ma mg + bv^{2}=ma - When...

I'm currently working on an engineering project for my high school engineering course, and the knowledge of physics I should have for this project is more than I actually know. I want to build a catapult that can shoot a tennis ball at an 8” target on the ground from 30 feet away. I want to take...

This is a hypothetical question that I am curious about.. Suppose we are trying to design a projectile that is intended to travel at high hypersonic velocities, on the order of mach 10 or 20, through air (you can assume sea-level density for argument's sake). Would an ideally sharp round...

I have to write the equation of motion for a projectile thrown vertically, under quadratic air resistance. The forces acting on the projectile then are, gravity and the quadratic air resistance. Now, both forces are opposing the projectile, would that mean that if I make gravity negative...

Homework Statement A drag racer, starting from rest, speeds up for 402 m with an acceleration of +23.0 m/s2. A parachute then opens, slowing the car down with an acceleration of -6.70 m/s2. How fast is the racer moving 3.35 102 m after the parachute opens? Homework Equations ? The...

Problem: To demonstrate the tremendous acceleration of a top fuel drag racer, you attempt to run your car into the back of a dragster that is "burning out" at the red light before the start of a race. (Burning out means spinning the tires at high speed to heat the tread and make the rubber...

Hi, I wanted to make an equation with Newtonian physics, but failed. Here's the problem: Consider an object with that ^ has m mass, and a built in drag & | magic motor that has P friction...

Hi guys I've been reading on the boards for a few days now and everyone here seems really helpful, so I've decided to come and ask for some guidence on a problem I've been having Homework Statement I have to find the terminal velocity of a smooth wooden ball. rho(ball)=420 kg/m^3...

Homework Statement For my Extended Essay I am modeling the flight path of a soccer ball under various conditions. Currently, I have a model for an extremely basic soccer kick with no spin and only gravitational forces, with no drag. My goal is to model the kick firstly with the addition of...

Homework Statement A particle of mass m is traveling along the x-axis with a constant horizontal velocity v0i. When the particle passes through the origin, it experiences a Drag Force which is proportional to the square of the particle's speed (Fd = - b/v^2i... drag coefficient b...

Prove this... A particle of mass m is traveling along the x-axis with a constant horizontal velocity v0i. When the particle passes through the origin, it experiences a Drag Force which is proportional to the square of the particle's speed (F[SIZE="1"]d = - b/v^2i... drag coefficient b...

As most of you know, the drag force equation is Fd=1/2*p*Cd*V^2*Cd*Ac. At terminal velocity, Fd equals weight. If you find the value of all the variables except Cd and V, you still won't have anything. But the terminal velocity equation is Vt= sqrrt of 2weight/p*Cd*Ac. So if V is terminal...

I know the equation for terminal velocity and drag coefficient. But I can't find one without the other. It's a real catch-22. I also don't know the Drag Force. HEEELP!

Hello everyone. I have researched from the internet that the drag force equation for projectile motion is either F= C p a v^2 or F= 0.5 C p a v^2. Which one is the correct one? The initial speed I am dealing with is about 20m/s. And what's the value for C for a normal tennis ball. Other sites...

Hey, is there any program that's easy to use for writing formulas on the computer (I'm thinking like a drag and drop type deal), preferably one that translates the formula to LaTex? I'm on Mac OS X. but I'm sure there has to be a web applet somewhere on the net that does this? thanks!

Homework Statement Need to energy dissipation by the drap force on a ball in free fall from height h and when it has reached terminal speed, assuming it happens before it hits thr ground. Drag force has magnitude bv^2, where b is drag coefficient and v is instantaneous speed of the ball...

Hi, I am designing an experiment for an individual project and it happens to involve aerodynamic. I wonder if someone can give me some idea of the drag coefficient of a square piece of flat paper (the normal 80grams photocopying paper) traveling through air against its face? (i.e. not...

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

Hello, please help me I have a question regarding drag force and Newton's law of motion. This is quotes from online pdf files from University of Toronto Scarborough. "the terminal velocity is F/b , where b is drag constant Let’s solve the equation of motion and see how this is reflected...

Ok, I think I'm getting a hold on this problem, but I want to make sure I'm in the direction... Homework Statement Let \inline{v_\infty} be the terminal velocity of a falling body in air. If the body is dropped from rest, find the expression for the speed as a function of time (1) if the air...

Ok so (UK) A2 Physics coursework time came, and I stupidly thought that projectile motion would be a fun investigation. But after just a little research I found it most challenging, it's taken me 'round the houses' via Reynolds numbers etc, and I've come to a halt as I'm kinda stuck. I plan...

Hi, First of all, thanks for taking the time to read my post. I have started writing my own Particle System and I'm having trouble calculating where a particle would end up over a period of time. I have decided to use 3 foces, gravity, buoyancy and drag. I also decided to skip friction...

Alright so far I've got: Force of Drag = (.5)(A)(p)(V^2)(Cd) The only thing is I keep getting a Fd that is larger than Fg. Could someone explain to me how to figure out the acceleration an object falls at when experienced to a certain drag? Ex: 9.8 m/s/s is a freefalling object...