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Air friction, or air drag, is an example of fluid friction. Unlike the standard model of surface friction, such friction forces are velocity dependent. The velocity dependence may be very complicated, and only special cases can be treated analytically.
An object slides down an inclined plane at a constant velocity if the net force on the object is zero. We can use this fact to measure the coefficient of kinetic friction between two objects. As shown in Example 6.11, the kinetic friction on a slope is f k = μ k m g cos θ f k = μ k m g cos θ.
4 Μαρ 2017 · Therefore, engineers devised a non-dimensional number, called the drag coefficient (C D), which quantifies the aerodynamic sleekness of the vehicle configuration. The definition of the drag coefficient is: where D is the drag force, ρ is the air density, U is vehicle speed, and S is the frontal area. One of the nice aspects of this formula is ...
There are several factors that can greatly impact a car’s acceleration, handling, and fuel economy, but air resistance has the greatest impact at high speeds and on windy days. During this process, aerodynamics plays an important role, which can be attributed to its science.
Friction is a force that opposes relative motion between systems in contact. One of the simpler characteristics of friction is that it is parallel to the contact surface between systems and always in a direction that opposes motion or attempted motion of the systems relative to each other.
For a body rolling uniformly, friction is zero in the absence of other forces. When a car accelerates, the friction force is forwards. For a body to accelerate, there must be an external force. There are two external forces here, gravity (useless for forward acceleration), and friction.
Friction caused by air is called air resistance or drag. Bikes, cars and other moving objects experience air resistance as they move through the air.
