What is Air resistance: Definition and 415 Discussions

In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, drag force depends on velocity.Drag force is proportional to the velocity for a laminar flow and the squared velocity for a turbulent flow. Even though the ultimate cause of a drag is viscous friction, the turbulent drag is independent of viscosity.Drag forces always decrease fluid velocity relative to the solid object in the fluid's path.

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  1. B

    What is a typical constant for air resistance in relation to velocity?

    Hey I am just wondering about something, air Resistance is proportional to the velocity in some cases or velocity squared in others. dV/dt=kv what is a typical constant for k, i know it varies so let's just say a baseball at sea level(im sure you all can guess why I am asking this...
  2. P

    Does air resistance affect projectile motion?

    Hi all, If someone threw a ball vertically & we want to calculate the time needed to for the ball to return back to his hand taking into account air resistance, would it be different if we ignore air resistance?? When they derive the known laws for the maximum height, range & time, did...
  3. J

    Including air resistance in the calculation of falling objects

    Hello all, I have a sort of basic physics question for you all. I was wondering where I might look to get some simplified math to calculate the amounf of air resistance on a falling object if I know the shape, mass, and volume of the object. I'm doing a lab experiment where I have to drop...
  4. G

    Sky divers air resistance balances with their weight

    When a car is travlling at constant speed, we say that the forward force is equal to the frictional force. How is that possible? Shouldnt the car be stationary? Samething with sky divers, when the air resistance balances with their weight, how is it possible that they still move downwards...
  5. M

    Air Resistance Lab Help (Logs)

    In this lab we dropped coffee filters from a given height (3 M) and want to determine their terminal velocity My problem is I don't know how to solve the log thing given. we have terminal velocity, V, in the formula Mg = bV^n which I change to V=(Mg/b)^(1/n) then to...
  6. M

    Air Resistance and projectile motion

    For projectile motion, how does one take air resistance into consideration? I have constructed a device to launch a projectile and I know how to deal with projectile motion without any air resistance, but I am unsure how I determine the range (the distance the marble/object will go) in the...
  7. K

    Air resistance and jet engines

    When a jet aircraft is flying at high speed doesn't the air impacting on the front of the engines compress the air before it gets into the compressor. And how fast does the combusted fuel leave an engine compared to the speed of airflow at the intake?
  8. M

    Deriving the Formula for Air Resistance and Viscous Drag Using Momentum

    How would one go about proving the formula D = 1/2C(rho)A(v^2) I have a suspicion momentum can be used to the show the derivation of this, right ?
  9. F

    Understanding Air Resistance Formula: Finding R, D, and p Variables

    the formula: R = (.5)DpAv^2 is used to determine how much air resistance (resistive force) is being placed on the object. R is the Resistive force. D is some dimensionless empirical quantity called the drag coefficient p is the density of air A is the cross-sectional area of the object...
  10. A

    Problems dealing with air resistance?

    Does anyone know how to solve for problems dealing with air resistance? For example: "The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W = 59500 N. The lift force L generated by the rotating blade makes an angle of...
  11. S

    Air resistance, how to calculate it?

    Im taking AP Physics as well as Calculas but haven't covered the topic of Air Resistance yet. I am trying to figure out what the air resistance would be on a baseball. Could someone help me out? Much thanks
  12. M

    Is sound effected by air resistance?

    i was thinking... sound fades off over distance... does this happen because of air resistance? i know there are a ton of factors involved in this... but is this one of the more important ones in it? if anyone has any ideas please post them :D
  13. E

    Air resistance of someone falling out of an airplane

    if someone falls out of a airplane that is horizontally traveling at 60m/s and goes into the ocean 3.0 seconds later with no air resistance what would the horizontal distance he travels while falling be. is the formula d=vt and the answer 180 m
  14. A

    Two bodies are falling with negligible air resistance

    Two bodies are falling with negligible air resistance, side by side, above a horizontal plane. If one of the bodies is given an additional horizontal acceleration during its descent, it 1. has the vertical component of its velocity altered 2. strikes the plane at the same time as the...
  15. dav2008

    Air Resistance Formula: Basics & Explanation

    Hm..well I am taking a Physics B course and we never covered the topic of air resistance.. So I was a little curious, so could anyone please give a brief explanation of the basics..or maybe some formula.. I was just wondering if it was really simple like the boyency force or something or...
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