Rotational Motion & Astrophysics - Definitions Flashcards
Angular Velocity
The rate of change of angular displacement
Angular Acceleration
The rate of change of angular velocity
Moment of a force
The turning effect it can produce
Moment of inertia
A measure of its resistance to angular acceleration about a given axis.
Depends on mass and the distribution of mass about a given axis.
Conservation of angular momentum
The total angular momentum before an impact will equal the total angular momentum after the impact, in the absence of external torque
Conservation of energy
The stored potential energy lost by an object is stored in the object as translational kinetic energy and rotational kinetic energy
Astronomical Unit
The average distance between Earth and the Sun
Gravitational field strength at a point
Force experienced per unit mass in a gravitational field
Gravitational potential
The work done by external forces in a moving unit mass from infinity to that point
Conservative field
The energy required to move mass between two points in a gravitational field is independent of the path taken
Escape velocity
The minimum velocity required to allow a mass to escape a gravitational field to infinity, where the mass achieves zero kinetic energy and maximum (zero) potential energy
Black hole
An object that the escape velocity equals the speed of light
Schwarzschild radius
The distance from the centre of a black hole to the event horizon
