tangential speed
the linear speed tangent to a curved path, such as in circular motion
rotational speed
the number of orations or revolutions per unit of time; often measured in rotations or revolutions per second or per minute. (scientists usually measure it in radians per second)
rotational inertia
that property of an object that measures its resistance to any change in its state of rotation: if at rest, the body tends to remain at rest; if rotating, it tends to remain rotating and will continue to do so unless acted upon by a external net torque
torque
the product of force and lever arm distance, which tends to produce rotation
torque = lever arm x force
torque equation
center of mass
the average position of the mass of an object. The ____ moves as if all the external forces acted at this point
center of gravity
the average position of weight or the single point associated with an object where the force of gravity can be considered to act
equilibrium
the state of an object in which it is not acted upon by a net force or a net torque
centripetal force
a force directed toward a fixed point usually the cause of circular motion
f = mv^2/r
centripetal force equation
centrifugal force
an outward force apparent in a rotating frame of reference. It is apparent in the sense that it is not part of an interaction but is a result of rotation -- with no reaction-force counter part
angular momentum
the product of a body's rotational inertia and rotational velocity about a particular axis. For an object that is small compared with the radial distance, it can be expressed as the product of mass, speed, and the radial distance of rotation
conservation of angular momentum
when no external torque acts on an object or a system of objects, no change of _____________ can occur. Hence, the ________ before an event involving only internal torques or no torques is equal to the angular momentum after the event.