Acceleration in UCM This is called centripetal Acceleration Now lets calculate the magnitude △v △v△R Similar triangles V R But△R=v△ t for sma△t △vV△t R So △R V R △tR Physics 121: Lecture 10, Pg 16
Physics 121: Lecture 10, Pg 16 Acceleration in UCM: This is called Centripetal Acceleration. Now let’s calculate the magnitude: v1 v2 v v2 R v1 R v v R R Similar triangles: = But R = vt for small t So: v v v t R = v t v R = 2 a v R = 2
Centripetal Acceleration UCM results in acceleration Magnitude a=v2/R =02R since v= OR Direction ( toward center of circle) Physics 121: Lecture 10, Pg 17
Physics 121: Lecture 10, Pg 17 Centripetal Acceleration UCM results in acceleration: Magnitude: a = v2 / R = R since v = R Direction: - r (toward center of circle) R a ^
Lecture 10. ACT 1 Uniform Circular Motion A fighter pilot flying in a circular turn will pass out if the centripetal acceleration he experiences is more than about 9 times the acceleration of gravity g. If his F18 is moving with a speed of 300 m/s, what is the approximate diameter of the tightest turn this pilot can make and survive to tell about it (a)20m (b)200m (c)2000m (d)20,000m Physics 121: Lecture 10, Pg 18
Physics 121: Lecture 10, Pg 18 Lecture 10, ACT 1 Uniform Circular Motion A fighter pilot flying in a circular turn will pass out if the centripetal acceleration he experiences is more than about 9 times the acceleration of gravity g. If his F18 is moving with a speed of 300 m/s, what is the approximate diameter of the tightest turn this pilot can make and survive to tell about it ? (a) 20 m (b) 200 m (c) 2000 m (d) 20,000 m
Example: Propeller Tip The propeller on a stunt plane spins with frequency f= 3500 rpm. The length of each propeller blade is L=80cm What centripetal acceleration does a point at the tip of a propeller blade feel? What is a here? Physics 121: Lecture 10, Pg 19
Physics 121: Lecture 10, Pg 19 Example: Propeller Tip The propeller on a stunt plane spins with frequency f = 3500 rpm. The length of each propeller blade is L=80cm. What centripetal acceleration does a point at the tip of a propeller blade feel? f L what is a here?