1. UB, Phy101: Chapter 5, Pg 1 Physics 101: Chapter 5 Application of Newton's Laws l New Material: Textbook Chapter 5 è Circular Motion & Centripetal Acceleration Demo

2. UB, Phy101: Chapter 5, Pg 2 You are twirling a ball on string. What happens if the string breaks ? a b c Answer: b v

3. UB, Phy101: Chapter 5, Pg 3 Acceleration in Uniform Circular Motion vv1vv1 vv2vv2 vvvv vv2vv2 vv1vv1 R RRRR centripetal acceleration a  v a ave =  v /  t

4. UB, Phy101: Chapter 5, Pg 4 Uniform Circular Motion (circular motion with constant speed) v R centripetal acceleration Instantaneous velocity is tangent to circle Instantaneous acceleration is radially inward There must be a force to provide the acceleration a

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9. UB, Phy101: Chapter 5, Pg 9 Chapter 5, Pre-Flight Questions Consider the following situation: You are driving a car with constant speed around a horizontal circular track. On a piece of paper, draw a Free Body Diagram (FBD) for the car. How many forces are acting on the car? 1 2 3 4 5 W f FNFN correct

10. UB, Phy101: Chapter 5, Pg 10 Chapter 5, Pre-Flight Question The net force on the car is 1. Zero 2. Pointing radially inward 3. Pointing radially outward W f FNFN  F = ma = mv 2 /R a=v 2 /R R correct For the car to stay traveling around a horizontal circular track, there must be a net force pointing radially inward, toward the center of the circle. If there wasn't, the car would drive in a straight line.

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12. UB, Phy101: Chapter 5, Pg 12 More about Centripetal Acceleration Define frequency f, period T, angular velocity  :

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