Physics Notes - Circular Motion free essay sample

The reverse is also true if an objects acceleration is equal to  v2r  (and perpendicular to the velocity) then the object must be going in a circle. If an object is moving in a circle at with a changing velocity, then the overall acceleration is not equation to the centripetal acceleration. However the acceleration perpendicular to the velocity (that is the part changing the direction) is still equal to  v2r 2. 6. 3 Identify the force producing circular motion in various situations Sometimes people will make reference to the centripetal force. This is not a real force, its a pseudo-force. In general the centripetal force is made up of many other forces and is the sum of those forces. This is not unlike the idea of a net force which is also generally the sum of multiple forces. If you have a ball on the end of a string and you swing it in a vertical circle the centripetal force or the forces causing the acceleration will be a combination of the  tension  from the string and  gravity. We will write a custom essay sample on Physics Notes Circular Motion or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page At the top of the circle the ball will be going slower than at the bottom (conservation of energy). Since the speed is lower at the highest point the centripetal acceleration will be reduced. The weight remains the same, so the tension must be reduced to maintain circular motion. While at the lowest point the ball will be moving faster and thus the centripetal acceleration will be increased, so the tension must have increased to maintain circular motion. The Tension and Weight are the forces causing the acceleration the ball is also moving in a circle so at the highest and lowest points  Tension+Weight=CentripetalForce. Some care should be taken with the sign (+/-) of the tension force as its direction changes throughout the motion. Take it a step farther: (2) Fnet=ma (3) T+W=ma (4) T+Wm=a=v2r