Unformatted text preview: axis but displaced from it by a distance d is given by 2 P CM Md I I + = Definition of Work done by a constant torque : 2 1 ( ) z z W = ⋅= ⋅∆ A rotating rigid body has Kinetic Energy : 2 1 2 K I ϖ = The Angular Momentum (a vector) of a point mass m is defined as L r p r mv = × = × r r r r r ( p mv = r r is the linear momentum of m and r r is the position vector that locates the point mass relative to the axis of rotation) The magnitude is sin L r p = ⋅ ⋅ r r r ; the direction is determined by the righthand rule. For a rigid body rotating about a symmetry axis, L I = r r Conservation of Angular Momentum : for any system of particles ext dL dt = ∑ r r From this it follows that constant L = r if ext = ∑ r . When the net external torque acting on a system is zero, the total angular momentum of the system is conserved (remains constant). Phys 0174 – Fall 2008 – P. Koehler...
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 Spring '08
 KOHLER
 Physics, Acceleration, Angular Momentum, Energy, Inertia, Kinetic Energy, Momentum, Work, Moment Of Inertia, Rigid Body, Rotation

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