Physics Help Forum Linear Speed? Angular Speed? Centripetal Acceleration?

 Periodic and Circular Motion Periodic and Circular Motion Physics Help Forum

 Oct 3rd 2013, 04:45 AM #1 Junior Member   Join Date: Sep 2013 Posts: 10 Linear Speed? Angular Speed? Centripetal Acceleration? a toy car moves around a circular track that has a diameter of 1.2m. It makes one complete revolution in 12secs. calculate the linear speed, angular speed and centripetal acceleration. can u pls tell me how to answer that?
 Oct 3rd 2013, 06:02 AM #2 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,310 Think it through this way: You can calculate the distance around the track from geometry: Circumference = pi times diameter. If it makes one complete revolution in T=12 seconds then its linear velocity is distance traveled divided by time = pi x D/T. The angular velocity is expressed in radians per second. One revolution = 2 pi radians, so the angular speed is 2 pi radians/12 seconds. The formula that you should remember is w = 2 pi/T, where w = angular velocity in radians/second and T = period of revolution. The centripetal acceleration is calculated using a = w^2 R, where w = angular velocity in radians/second (which you just calculated) and R = radius. You should memorize this formula.