 Rotation – object spinning around an internal axis. Ex: a spinning top  Revolution – object spinning around an external axis. Ex: Earth moving around the Sun

 Tangential Speed– the distance covered per unit of time.  For circular motion distance = 2πr  Expressed in m/s  Rotational Speed – number of rotations per unit of time. Expressed in RPM (rotations per minute)

 If you are standing in the exact center of a record/disc that is spinning… - you have no tangential speed but you do have rotational speed.

 Rotational speed remains constant no matter where you are on the disc  Tangential speed increases the further away from the center you get.

Centripetal Force DemonstrationCentripetal Force Demonstration #1

 Centripetal Force – a center seeking force - causes an object to follow a circular path - Circular path Demo Circular path Demo m – mass a c – acceleration v – tangential speed r – radius

 Centrifugal force - Center fleeing force  is a not a real force  What you feel is actually inertia. ▪ Your body is trying to go in a straight line while the object you are in is turning. ▪ Hence you feel as if you are being pulled outward (away from the center).

 Simulated Gravity - can be created if an object spins fast enough …Small objects need to spin rapidly …Large objects need to spin slower and still achieve the same gravitational effect. ***Could be used for a space station

 Torque – produces circular motion  Torque = perpendicular force applied times the lever arm (distance from the fulcrum)  Fulcrum is the pivot point  Torque = F ┴ x d  (Nm) = (N) x (m)  Balanced torques ( balanced see-saw ) ▪ F x d = F x d

 The object is not rotating  The Net Torque acting on the object is zero