Drag Definition and 751 Threads

Homework Statement A stone with mass m = 1.8 kg is thrown vertically upward into the air with an initial kinetic energy of 310 J. The drag force acting on the stone throughout its flight is constant, independent of the velocity of the stone, and has a magnitude of 2.5 N. (a) What is the...

I know that standard formula is, FD = 1/2 CD *ApV^2 FD = Drag Force. SI: N CD = Drag Coefficient. SI: Dimensionless (Typical Values) A = Coss-sectional Area perpendicular to the flow. SI: m2 r = Density of the medium. SI: kg/m3 v = Velocity of the body relative to the medium. SI: m/s...

Homework Statement I know that standard formula is, FD = 1/2 CD *ApV^2 FD = Drag Force. SI: N CD = Drag Coefficient. SI: Dimensionless (Typical Values) A = Coss-sectional Area perpendicular to the flow. SI: m2 r = Density of the medium. SI: kg/m3 v = Velocity of the body relative...

2 cars drag racing question... Homework Statement The first car has a constant velocity of 40 m/s and moves 10 m before the 2nd car starts moving. The second car speeds up with an acceleration of 3.6 m/s^2. What is the time and the displacesment before the 2 cars actually meet...

Homework Statement A top fuel drag racer with a mass of 500.0 kg completes a quarter-mile (402 m) drag race in a time of 4.3 s starting from rest. The car's final speed is 115 m/s. What is the engine's average power output? Neglect friction and air resistance. Homework Equations P = W/T...

Homework Statement A gun is fired straight up. Assuming that the air drag on the bullet varies quadratically with speed. Show that speed varies with height according to the equations v^2 = Ae^(-2kx) - g/k (upward motion) V^2 = g/k - Be^(2kx) (downward motion) in which A and B are...

Homework Statement Studetns examine the aerodynamics of a model car which has a drag force in air of 10 N at 10 m/s. They wish to estimate what the drag will be for a full scale model, and the energy lost on a given trip. The drag coefficient C remains constant C= 0.6. The cross-sectional...

Homework Statement If there were no air drag, how fast would drops fall from a cloud 1.6 kilometer above the Earth's surface? Homework Equations am i heading in the right direction if not what am i doing wrong? The Attempt at a Solution i tried converting to m first then i...

Homework Statement Consider a particle of mass m whose motion starts from rest in a constant gravitational field. If a resisting force proportion to the square of the velocity (i.e. kmv^2) is encounterd, show that the distance s the particle falls in accelerating from v0 to v1 is given by...

Homework Statement An object with mass 10kg is dropped from a height of 200m. Given that the constant k in the equation is 2.5Nsm^-1 mv'(t) = −mg − kv(t) approximately how many seconds does the object hit the ground? Homework Equations v' + (k/m)v = -g The Attempt at...

Homework Statement A baseball, with mass m = 0.145 kg, is thrown directly upward from z(0) = 0 m, with initial speed v(0) = 45 m/s. The air drag on the ball is given by Cv2, C = 0.0013 Ns2/m2. Set up a diff. eq. for the ball's movement and solve it for both v(t) and z(t). m = 0.145 kg C =...

hi i need to calculate the drag coefficient of a rotor bade(with two blade).infact i need to calculate the torque by drag,then power required for rotate that rotor on a fixed test stand. who knows about what formula or chart, diagrams... thanks in regards sadegh

A reasonably large object moving though air experiences a drag force proportional to the square of its speed. If an object is falling vertically downward at half its terminal speed, how does the drag force acting on it compare to the force of gravity? express your answer as a multiple of Fg

So I was looking at MIT iTunes U physics videos, and the professor talked about regimes I and II in the video about drag forces. I think regime I has to do with the temperature of the medium and regime II has to do with the density. But, I cannot find that information in my 1st semester physics...

Homework Statement hile playing pool on a cruise ship, you accidentally hit the cue ball over the railing and it falls into the ocean below. If the cue ball (a sphere of diameter = 57.15 mm, m = 160 g) reaches a terminal velocity of 1.55 m/s in the water (), what is the drag coefficient of...

Hi, I'm looking for the formula to get the velocity value from a drag value. I found plenty of resources to do it the other way around (velocity to drag) but no luck to get it the way I need it. This website seems to have it but they don't provide the rule and they actually want money to...

Does anyone have a solution (approximate is fine) for the Drag equation? What I mean by this is that I need to be able to get position and velocity as functions of time for a body falling through air from rest. I managed this for a viscous liquid where drag is approximately linearly...

Can anyone help me work out the air resistence on a wire as it moves along its length? I think it would only experience skin friction if it moved like this and the wire was smooth, so does anyone know how to calculate this? I am having difficulty looking it up.

Homework Statement A 0.3m diameter cork ball (density 210kg/m^3) is tied to an object on the bottom of a river as is shown in fig B3. The weight of the cable and the drag on it can be neglected. Assume the water viscosity u is 1.12x10^-3 Ns/M^2 and the water density p is 1000kg/m^3, and the...

hey all I have a question and I want to quickly get an answer how to calculate projectile motion with drag a formula even if it is hard would be good mvh. patrick sorry my spelling I'm from abroad

I am interested in calculating the drag force acting on simple objects (cube and sphere) as they passes from a liquid (water) into a gas (air). I can calculate the drag force as the objects travel through a uniform medium, but I am wondering how the drag force on an object changes as it passes...

hi, I am currently building a drag racing game and I am wanting it to be as physically accurate as possible. my question is, when a driver drops the clutch in a vehicle what needs to be taken into account to calculate the force acting on the vehicle while the wheels are spinning? is it possible...

Homework Statement I need to find an expression for the minimum drag coefficient, C_D, of an aircraft during straight and level flight. Homework Equations C_D=C_{D_0}+kC_L^2 Where: C_{D_0} is the profile drag coefficent C_L is the lift coefficient k is just a constant The Attempt at a...

hi small question in the drag coefficient formula for boats and ships, is the reference area, the surface area of the submerged part of the ship/boat? demson

Homework Statement whats the energy required to drag a block a distance L Homework Equations coefficiant of friction between block and floor = \mu density of block = p force*distance = change in kinetic energy The Attempt at a Solution friction acting against movement Fr = \mumg m...

Homework Statement I made a wind tunnel for a science project and i am trying to determine its windspeed. I decided to suspend a pingpong ball on a string in the wind tunnel and measure the angle change. But to do this i need to calculate the drag force and i cannot do this without knowing the...

Hi In a Drag problem, I'm trying to calculate the drag force but I don't know the drag coefficient? Is there any way to calculate it? Thanks

Homework Statement I need something like the equations of motion, but accounting for drag as given by the http://en.wikipedia.org/wiki/Drag_equation" . Particularly for: Homework Equations & v && = v_0+at \qquad & s && = s_0 + v_0t + \tfrac12 at^2 \qquad The...

Homework Statement I'm writing a lab report on drag on a non-rotating cylinder. The drag coefficient is calculated using the Pressure co-efficient. The problem I'm facing is that my lab states that the pressure on the cylinder can be predicted by \left(p-p_{0}\right)_{max} \times cos(\theta)...

I've been told I can derive the drag equation from momentum and force. I have also found a site that has a similar question but no solution. http://www.physics.umd.edu/perg/abp/TPProbs/Problems/D/D30.htm I have an idea of how to get a solution but get stuck.

hey,everyone,could you please explain to me the terms Terminal Velocity and Drag in detail,as my exams are coming up.

Hello, First time post long time lurker! I've got an interesting project I am working on which involves a few MechE subjects. The overall goal (for now) is to determine the drag force of a cylindrical cone headed object in sand under various pressures. The movement of the cylinder is the tricky...

Drag Coefficient out by a factor of 10, can anyone help?? Im doing an experiment on the drag of a sphere and am trying to work out the drag coefficient. From looking at data online this should be around 0.5 (its a smooth sphere). Using a wind tunnel I measured the drag for various sizes of...

Homework Statement Need to solve the differential equation which models the velocity of a sky diver. Homework Equations dv/dt = -9.8 + 0.0045Av^2 where A is cross sectional area (assume 0.75m^2) v(0) = 0 The Attempt at a Solution ok the problem is to find v(t) as a function time. as...

Homework Statement For a touring bicyclist the drag coefficient C(where f of air = 0.5CApv^2) is 1.04, the frontal area A is 0.462 , and the coefficient of rolling friction is 4.60×10−3. The rider has mass 53.0kg, and her bike has mass 11.1kg. Note: p is density of air (1.2kg/m^3) To...

Hi Can anyone explain in detail about drag increase in supersonic speed Why and how drag increases in Blunt shape nose cone to compare with Sharp nose cone at supersonic speed? Ryan

If differential drag on a four cup anemometer causes its rotation, how does one calculate the differential drag on a specific size cup and with a specific wind velocity assuming the wind is constant and in the same horizontal plane as the four cups.?

Homework Statement I want to numerically simulate a fall with air drag. In class, we used these equations to produce a table simulating free fall (using a ti calculator): dt=0.1s a=9.81m/s² tn+1=tn+dt vn+1=vn+a*dt xn+1=xn+vn*dt When I compared that system with the curve produced by the...

This is not a homework problem, just an idea I had. If we have a sphere which is being accelerated in space by a force \vec{F} and we take the drag into account, what would the displacement be after t seconds? If the drag force is \vec{D}=-c_1v-c_2v^2, then the acceleration would be...

Hi i'm writting a report on road vehicle drag. Are there any free resources online / journals that i can use for research? my questions: Relationship between Drag and Turbulence what does a engineer design in a car? (engines, the body-aerodynamics..) and the relationship between...

Hi, I've been toying around with a cheap slingshot and some steel balls and cannot figure out how to calculate the velocity of the projectile at a given time/distance. What I've done so far: I derived a fairly accurate formula for the potential energy of the slingshot by measuring the...

I have been studying surface tension from my textbook, when I came across a question in which a thin circular plate is placed over water. The surface tension of the water is given. The minimum force required to pull away the circular plate is asked. The dilemma, I am in is in which direction...

Hey guys, I current picked up Fundamentals of Aerodynamics by John D. Anderson Jr. and am having a little bit of trouble understanding some of the equations i am given. This is the first aero book I've picked up so I am not too familiar with aero concepts or terms yet. On page 20...

Trajectory of a bullet with drag In most physics books, they pass over drag problems because of their difficulty. However, I had to do one for a mid-term for a physics class. When the velocity is low (tens of m/s or less), then the drag is proportional to the velocity and the math is quite...

1. Homework Statement Question Details: A "Christmas Tree lighting system is used to start a drag race. The inputs to the system include a start button, a reset button, and two start line sensors. The outputs include lines for Red, Yellow, and Green lights and two Fault lights. When the...

Homework Statement Question Details: A "Christmas Tree lighting system is used to start a drag race. The inputs to the system include a start button, a reset button, and two start line sensors. The outputs include lines for Red, Yellow, and Green lights and two Fault lights. When the operator...

Hello and thanks to all who read this. Recently I've just been messing around with air drag equations, trying to extend applied maths problems to include air drag. And I've hit a road block, at least with regards to my knowledge anyway. I've been using the F_drag = 1/2 P (mass density of...

Homework Statement A speed boat is accelerating at 5 m/s/s. If the Boyant force (the force the prevents the boat from sinking) is 3140 N and the thrust that the motor exerts on the boat is 1876 N, what is the drag on the boat (drag in a fluid is a like friction on land). Homework...

Homework Statement A stone with weight w is thrown vertically upward into the air from ground level with initial speed v0. If a constant force f due to air drag acts on the stone throughout its flight, (a) show that the maximum height reached by the stone is h = \frac{v_0^2}{2g(1+f/w)}...

Homework Statement An automobile is traveling at speed of 80 km/h through heavy rain. The raindrops are falling vertically at 10 m/s and there are 7*10^-4 kg of raindrops in each cubic meter of air. For the following calculations assume that the automobile has the shape of a rectangular box 2m...