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Physics 201 Ch 12-15
Question | Answer |
---|---|
what is α | (Alpha) Angular Acceleration. -> Rate of change of angular velocity. In SI units, it is measured in radians per second squared (rad/s2) |
what is ω | (Omega) The rate of change of ang. displacement angular speed (rotational speed) of an object and the axis about which the object is rotating. Unit=rad/s. The direction is perpendicular to the plane of rotation,(righthand rule) |
α formulas | dω/dt. Torque = I*α |
Angular Momentum | L=r x p = Iω Angular momentum can be expressed as the product of the body's moment of inertia, I, (i.e., a measure of an object's resistance to changes in its rotation rate) and its angular velocity ω |
Torque | Torque is defined as = r x F = r F sin(theta). (cross product). Torque is a measure of how much a force acting on an object causes that object to rotate. |
ω formulas | ω*radius=velocity ω= V/r ω= delta x / delta t V=(delta x r)/(delta t) |
Cross product | If we let the angle between A and B be theta, then the cross product of A and B can be expressed as A x B = A B sin(theta) |
Every point on a rigid body rotating about an axis has the same ang. vel. ω and ang. acc. α. | Newton's second law for rotational motion is α=(Torque_net)/I |
conservation of energy? | E_final = E_initial Rolling E = K_rot + K_cm + U_g =1/2 Iω^2 + 1/2 Mv_cm ^2 + Mgy_cm L = I ω |