1. CIRCULAR MOTION

2. WHAT IS UNIFORM CIRCULAR MOTION The motion of an object in a circle at constant speed. However, direction and therefore velocity are changing. This means the object is constantly accelerating toward the center. Example: a Ferris wheel Any object that revolves about a single axis (axis of rotation) undergoes circular motion For the Ferris wheel the axis of rotation is perpendicular to the side of the wheel and passes through the center

3. Looking closer Centripetal acceleration- the acceleration of an object in circular motion acting toward the center of the circle Centripetal Force - the force which acts on an object toward the center of the circle to produce centripetal acceleration Centrifugal Force - the equal and opposite reaction to centripetal force

4. EQUATION FOR CENTRIPETAL ACCELERATION Acceleration is acting toward the center Velocity is acting tangent to the circle The equation becomes – a c =v t 2 /r Where: a c is centripetal acceleration v t is tangential velocity r is the radius

5. EQUATION FOR CENTRIPETAL FORCE The net force acting on a circling object is perpendicular to its motion The equation becomes – F c =ma c F c is centripetal force m is mass a c is centripetal acceleration

6. AN EXAMPLE An object with a mass of 5.0 kg moves in a circular path of radius 0.50 meters at a speed of 10. m/s. Calculate the centripetal acceleration and the centripetal force.

7. THE SOLUTION a c =v t 2 /r = (10. m/s) 2 /(.50 m) = 2.0 x 10 2 m/s 2 F c =ma c =(5.0kg)(10.m/s) 2 /(.50m) = 1.0 x 10 3 N