Physics October-08-08

# Physics October-08-08 - The net force is the zero a y = 0....

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Physics October- 08-08 Drag When an object travels through a liquid or gas, like friction it opposes relative motion. What determines how much drag we get are the fluid (density, viscosity, and compressibility), the object (shape and the size), and the flow (the speed and direction, as well as smooth vs. turbulent flow). If all other factors are constant, the drag force is proportional to the frontal area of the object. When the shape of the object takes effect on drag, it has a drag coefficient C d . If the object is blunt and the flow is fast enough that there is turbulence in the wake of an object, the drag force depends on the density of the fluid, the shape and size of the object, and the velocity of the flow. D = ½ C d p A v 2 Considering an object falling from rest, eventually the drag force becomes equal to the force of gravity.
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Unformatted text preview: The net force is the zero a y = 0. The speed no longer changes and the object is said to have reached terminal velocity. Terminal velocity causes the net force on an object to become zero. ∑F y = D – mg = 0 D = mg v 1 = (2mg/C d p A)-1/2 Circular Motion Centripetal acceleration is a center seeking “force”. Your acceleration vector will always point to the middle. The magnitude of the acceleration was: v 2 /r This centripetal force is not a special type of force, it is just another force that we are already familiar with (ex. Gravity or tensional force.) ∑F = mv 2 /r As a car travels around a corner, it is STATIC friction. (As the wheel travels it hits a specific point each time it turns)....
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## This note was uploaded on 04/04/2009 for the course PHYS 1020 taught by Professor Campbell-brown during the Spring '09 term at UWO.

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