Velocity with Linear DragFor an object that is acted upon by its weight, mg, and subject to a drag force proportional to its velocity bv, the general form for the velocity is given by the expression below. For an object in a fluid, you must use an effective force mg' to account for the buoyancy of the fluid. For viscous drag, the drag coefficient b may be expressed in terms of the viscosity of the fluid. This velocity expression may then be integrated to obtain an expression for the distance.

Index Fluid friction  

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Distance with Linear DragFor an object that is acted upon by its weight, mg, and subject to a drag force proportional to its velocity bv, the general form for the distance traveled is given by the expression below. For an object in a fluid, you must use an effective force mg' to account for the buoyancy of the fluid. For viscous drag, the drag coefficient b may be expressed in terms of the viscosity of the fluid. You can take the derivative of this distance expression to obtain an expression for the velocity.

Index Fluid friction  

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Velocity Graph, Linear DragThis behavior of velocity as a function of time would be expected for an object released from rest in a viscous medium where the resistance was proportional to velocity. The g value would be adjusted if there was significant buoyancy, and usually is then written g'.

Index Fluid friction  

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Penetration of a Viscous Medium

Index Fluid friction  

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