What is Drag: Definition and 747 Discussions

Hi, I have been doing an experiment at school looking into how the angle of a cone affects the time it takes for it to fall 2m. The data consistently shows an inverse relationship but it is unclear whether or not they are inversely proportional i.e. if the angle doubles, the time taken to fall...

Homework Statement I am trying to show that the pressure drag acting on a sphere is 2πμaU by integrating around the surface of the sphere where U is the speed of the fluid the sphere is in, a is its radius, and μ is the viscosity. Homework Equations The pressure at a given position r can be...

Homework Statement Using a wind tunnel to measure force and velocity at different drive %, we obtained some data for drag. We used one dimpled sphere and one smooth sphere. There are a couple of questions I am stuck on. "The force you have measured is known as the drag force and can be...

How i can know the magnitude of lift and drag force from ansys cfx?

Homework Statement Given the equations a) find the solution to the problem (1) in vectorial form, by first writing equation (1) in component form and then solving the two parts separately. These can then be combined to obtain the vector form of the solution. b) solve the results of the...

Hi , please i want to know if i have flat plate (rectangle) but its fixed like pendulum (fixed from one end and free at the other end and can rotate around this fixed end) i want to know the drag force due to air on this plate?

If the number of wheels on a vehicle are reduced from four to three or two (assuming problem of balance is taken care of), will it reduce the amount of energy spent on all resistance (such as friction/slippage at tyres, rolling resistance etc) faced by vehicle at the wheels. It is also assumed...

Why drag force doesn't Depend on the mass of the Object?

Hey Guys, I'm on a rocket team at my university and we are attempting to figure out the force of opening acting on some of our parachutes. Typically this is done using the following equations, in particular, the one in the top right corner. This is where our trouble begins. In the Recovery...

Hi! I was wondering how I could come up with a differential equation for projectile motion on a 2D plane when air resistance is not negligible. I'm trying to guess the position of a projected ball at a certain time period by approximating the coordinates using the Euler's method. Here, I would...

The force of drag is proportional to velocity, but with a projectile velocity isn't constant, so how could i calculate the energy lost due to drag? The projectile in question is being shot straight upwards, so that may make this problem much more simple.

Homework Statement https://i.imgur.com/WPAKuf4.png seeking G(s) = \frac{\theta_2(s)}{\tau(s)} Homework EquationsThe Attempt at a Solution What does it mean when the viscous drag is parallel to the axis of rotation?[/B] It also turns out that this system needs two equations. I can sort...

Does anyone know what the drag coefficient of a windsock is?

Hi everyone I was reading about drag, and didn't quite find what I was looking for. A general drag equation is : 0,5 x ρ x u² x Cd x A, where there are some drag coefficients that have been found during laboratory experiments. Let's say a sphere with a radius of 1m is traveling at 2m/s under...

Here's a crude model rocket fin made out of a material called Coroplast (corrugated plastic): And here's the exact same fin with the flutes cut out from all around the edges, allowing the edges to be squeezed shut and sealed with tape: It may look like there are small openings, but...

As most of you know real racecars have flat bottoms, rear diffusers and in the front well... a variety. So to keep this simple. I am building a car with a flat bottom and rear diffuser, car raked at 4 deg, diffuser at 14 (all details will be adjusted based on learned info) and nothing on top or...

Homework Statement I'd like to understand Drag Force better; but school always ignores it. Thus, I'm asking this purely out of obssession. I'm picturing a scenario where a non-constant force is pushing an object horizontally, ignoring friction. But, I'd like to understand how Drag Force...

Consider an artificial satellite orbiting the Earth and suppose that the atmosphere co-rotates with the Earth. I need to calculate x, y and z components of the atmospheric drag. I know how to calculate the drag in a non-spinning atmosphere and I have all the data to do that, but the Earth’s...

Hi there people, I am Leroy Leon, a film maker and playwright in Nigeria, and I am writing some science fiction films and I need answers with questions on Aerodynamics, slipstream and drag. So, my question is, if I want to create a land vehicle that can travel at hypersonic speeds, the...

I was looking for the derivation of stoke's drag F=6πηrv But I'm only getting the derivation by dimensional analysis. Can anyone please provide it's real derivation? I'll really appreciate it.

Homework Statement A saucer of mass 1.75x10^9 enters 1.the gravitational field of PlanetX and enters its atmosphere; the gravitational field of the planet is 10.6 m/s2 and is considered uniform throughout the 80-km thick atmosphere. If the saucer enters the atmosphere at 460 m/s and slows...

Homework Statement Let's have a cylinder in air tunnel. The air is flowing around cylinder. I want to calculate a net force acting on the cylinder. Part of the incoming air hits the cylinder and its trajectory direction changes. For that reason we can see straight behind the cylinder lower...

Homework Statement Consider a point mass of mass m suspended from an ideal, massless spring. Let ##\theta ## be measured from the vertical. Find the displacement of the mass as a function of time if the spring is initially stretched/compressed a distance ## l_0 ## and has an initial velocity...

Homework Statement An aircraft has a mass of 1100kg and a wingspan of b=9.75m. the surface of the wing is 15m2 and its span effciency factor e=0.90. the parasitic drag at zero lift of the aircraft CD0 is 0.0225. Take density of the air to be 1.225kg/m3 The aircraft has lost power and is...

Homework Statement An aircraft has a mass of 1100kg and a wingspan of b=9.75m. the surface of the wing is 15m2 and its span effciency factor e=0.90. the parasitic drag at zero lift of the aircraft CD0 is 0.0225. Take density of the air to be 1.225kg/m3 The aircraft has lost power and is...

I have two values for the initial velocity of a projectile through water. One is measured experimentally and the other a theoretical value for initial velocity. The measured value is 23.75m/s The theoretical value is 26.3m/s Resistance forces were not accounted for in this calculated value. To...

Homework Statement A submarine engine provides maximum constant force ##F## to propel it through the water. Assume that the magnitude of the resistive drag force of the water experienced by the submarine is ##kv##, where ##k## is the drag coefficient and ##v## is the instantaneous speed of...

If air drag is a factor, how will it affect a projectile’s trajectory qualitatively? Its velocity? Its acceleration?

I'm a computer scientist currently developing projectile simulators. My software will factor in drag coefficients of various shaped projectiles as well as gravity, air pressures, air density and temperatures at various heights. I am familiar with the drag formula but it's only useful up to Mach...

I'm writing a real time 3D physics simulator that simulate bullet ballistics. Can I use the air drag formula that factors in drag coeficient and outputs drag force to calculate how deep a bullet will penetrate a target material? Say I substitute air pressure with target material density. And...

Hello everyone, I am working on a 3.2 meter wing span electric aircraft with another group of 30 engineering students. In calculating the induced drag and lift for preliminary calcs I am a little confused as to whether I need to include the width of the fuselage in the wing span(b) for induced...

A vehicle loses Kinetic Energy because of aerodynamic resistance. But taken into account the conservation of energy, to which type of energy is the "lost" Kinetic Energy transformed? Is this Kinetic Energy transformed into heat just like friction transforms the kinetic energy of a sliding object...

Homework Statement I plotted the drag polar graph (Drag coefficient vs. lift coefficient) for an aircraft and are required to find the equation of the drag polar to determine values for [C][/D0] and k, using the graph or any other method. I've plotted the graph which I've included. Homework...

Hi Great Engineers, Need you help. I am required to calculate drag load on sticker to ensure it is not peeling off in operation. The vehicle may moves as fast as 220 km/hr with rectangular sticker size of 30 cm x 40 cm, thickness 0.0635 mm on its body. Wind direction is parallel to 40 cm length...

How does air resistance change the maximum height of a projectile ?

Motion relative to the CMB rest frame creates a dipole moment in the wavelength of CMB photons in the direction of motion. Observations suggest that the Earth has a motion relative to CMB rest frame of 600 km/s. As indicated in this study, for a spacecraft at a speed we shall dub 'ludicrous...

I have seen many examples of the EOM for a rocket derived for the following cases: No gravity, No drag Gravity, No drag No gravity, linear drag (b*v where b is a constant) I have never seen Gravity, linear drag Gravity, quadratic drag I took John Taylor's two examples of linear drag and...

Homework Statement A boat with initial speed vo is launched on a lake. The Boat is slowed by the water by a force F=-αeβv. Find an expression for the speed v(t), and find the time and distance for the boat to stop. Homework Equations Drag force F=-αeβv alpha and beta are not specified as to...

Homework Statement Calculate the ratio of the drag force on a jet flying at ##1200 km/h## at an atttude of ##15 km## to the drag force on a prop-driven transport flying at half that speed and altitude.The density of air is ##0.38(\frac {kg} {m^3})## at ##10 km## and ##0.67(\frac {kg}...

Hello all, I have browsed this forum occasionally when I had questions and threads showed up on a search. I have been stumped by a problem, so I decided to create an account and see if anyone could help me out! 1. Homework Statement A coal barge 1000 ft long and 100 ft wide is submerged in a...

I've been working on a little project recently and I've been scratching my head over this one problem, is there a way to calculate how far an object will travel while drag is taking effect. Assuming there is no gravity or any other forces acting on the object, if we take it's velocity, mass, air...

To find the firing angle to hit a target at a given distance using the initial velocity and gravitational acceleration, we use the formula: Angle = Firing XDist = Distance the target is from the gun along the X axis YDist = Distance the target is from the gun along the Y axis Angle =...

This is not a homework question, I'm just curious. Suppose you had a sailboat sailing on calm water. Let's say the sailboat is capable of sailing at 10 knots under the current wind conditions using only its sails. Now say the sailboat had a small propeller motor that was capable of propelling...

Is it the typical "get some results and stack the maths together and chuck in some constants to make it fit to get some approximation" or do we understand the rules behind it to derive the formula, such as how the molecules repel each other and how energy is transferred depending on temperature...

Hello everyone, I am making a paper on the possible applications for nuclear fusion. One of these possible applications is a Bussard ramjet. I'm trying to calculate if Bussard ramjets are feasible, based on their thrust and the drag they experience. A Bussard ramjet would use a very big...

I just learned how stellar abberation and the ether theory while studying Robert resnick's book. What I'm thinking is how the sky would look IF ether were to exist and be dragged along the Earth as it revolved the sun. Since Earth's local supply of ether is moving along with it i.e. rest w.r.t...

Guys,, please check my own way to get Drag coefficient and Terminal Velocity by given Drag force,.. okay,, lets for example: we know drag force is Fd= Cd*pf*v^2*A/2,, ill give little example (Cd=.02)*(pf=1027kg/m^3)*(v^2=.0025m/s)*(A=24m)/2 =( Fd .6162N) so drag force is .6162N,, okay..according...

Homework Statement I forgot if the deceleration is -0.003v or same here -0.003v2 Homework Equations v = u + at (first acceleration) dv/dt = a (deceleratioin) = -0.003v^2 The Attempt at a Solution From first equation, 342.2 = 0 + 30*t1 t1= 11.407s From 2nd equation, dv/v2 = -0.003...

I have been around Sailboats all my life. For the last 25 years I have built and raced r/c model sailboats. My current question, I hope, can be more of a discussion than just a simple question and answer. Since I am into the design of all aspects of boat and sails. I have a question about...

Homework Statement Consider a particle in a gravitational field that is also subject to a resisting force proportional to the velocity squared ( Fdrag = + or - cv2). a) Find the terminal velocity, vT, for the object as it falls. b) Show that for an object dropped from rest that the velocity...