chapter 8 Flashcards
(12 cards)
Tangential Speed
The linear speed tangent to a curved path, such as in a circular motion.
Rotational Speed
The number of rotations or revolutions per unit of time; is often measured in rotations or revolutions per second or per minute. (Scientists usually measure it in radians per second).
Rotational inertia
The property of an object is to resist 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 continues to do so unless acted upon by an external net torque.
Torque
The product of force and lever-arm distance, which tends to produce or change rotation: Torque= lever arm * force
Center of mass (CM)
The average position of the mass of an object. The CM moves as if all the external forces acting at this point.
Center of gravity (CG)
The average position of weight or the single point associated with the object where the force of gravity can be considered to act.
Equilibrium
The state of an object on 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
An outward force is apparent in a rotating frame of reference. It is apparent in the sense that it is not part of interaction but is a result of rotation- with no reaction- force compartment.
Linear momentum
The product of the mass of an object and its linear velocity
Angular momentum
the product of a body’s rotational velocity about a particular axis. For an object that is small compared with the radial distance, angular momentum can be expressed as a product of mass, speed, and radial distance of rotation.
Conservation of angular momentum.
When no external torque acts on an object or a system of objects, no change of angular momentum can occur. Hence, the angular momentum before an event involving only internal torques or no torques is equal to the angular momentum after the event.
