Rotational Motion & Astrophysics Flashcards
What is the angular velocity of a rotating object defined as?
The rate of change of angular displacement or the change in angular displacement per unit time
What is angular acceleration defined as?
The rate of change of angular velocity
What is tangential acceleration defined as?
The rate of change of tangential or linear velocity
What is centripetal acceleration defined as?
The rate of change in linear velocity
What direction is centripetal acceleration always towards?
The centre of the circle
What is centripetal acceleration always at a right angle to?
The tangential acceleration
What is torque defined as?
The product of radius and force applied at that radius to an axis of rotation.
What is the moment of inertia of a mass defined as?
A measure of its resistance to angular acceleration about a given axis.
When is angular momentum conserved?
When two or more objects collide in the absence of external torques
What happens when torque does work on a body to make it rotate?
It gains kinetic energy
What is gravitational field strength defined as?
The force per unit mass at a point.
How are satellites held in orbit around the Earth?
It is as a consequence of the Earth’s gravitational force which provides a centripetal force on the satellite.
What is gravitational potential at a point in space defined as?
The work done by external forces to move unit mass from infinity to that point
What is the value of both gravitational potential and gravitational potential energy at infinity?
Zero
What is gravitational potential proportional to?
1/r
