Conceptual Physics Notes on Chapter 9 CircularMotion

Circular Motion All objects turn around what is known as a AXIS. This motion is called ROTATION or spin. The spin is around a internal axis.

Circular Motion Motion around an external axis is REVOLUTION

Circular Motion LINEAR SPEED – distance moved per unit of time (Ch. 2). TANGENTIAL SPEED – distance in a straight line tangent to a circle.

Circular Motion ROTATIONAL SPEED – (sometimes called angular speed) is the number of rotations per unit of time.

Circular Motion Centripetal Force –Centripetal means “Center seeking”. –Centripetal is given to any force that is directed at a right angle to the path of a moving object.

Circular Motion Centrifugal Force –Centrifugal means “Center Fleeing”. –This is a fictitious force.

Circular Motion NOTE: The exact relationship is…. F = mv 2 /r F = Force m = mass v = velocity v = velocity r = radius r = radius

Circular Motion Centripetal Force vs. Centrifugal Force

Circular Motion Applications : –Simulated Gravity –NASA Space Station