Define angular velocity
The rate of change of angle of an object moving in a circular path
Define centripetal force
The resultant force towards the centre of a circle
Define centripetal acceleration
Acceleration towards the centre of a circle that causes the resultant centripetal force
How are centripetal force and velocity related? (2)
Centripetal force always acts perpendicular to velocity
There is no component of force in the direction of motion so the speed remains constant
Why are objects in circular motion accelerating if they have constant speed?
The direction is constantly changing so their velocity is changing, meaning they have acceleration
How is linear velocity related to radius?
For any object with constant angular velocity, linear velocity is directly proportional to the radius
How can circular motion be investigated using a bung? (2)
Use a bung attached to a weight using a piece of string
Swing the bung in a horizontal circle so that the suspended weight stays stationary; mg = centripetal force
Motion in a vertical circle (3)
Centripetal force is constant at all points
At top of circle, centripetal force = tension + weight
At bottom of circle, centripetal force = tension - weight
