"Not everything that counts
can be counted, and not everything
that can be counted, counts."

- Einstein



Video Instruction




 I. Uniform Circular Motion


Why can it be said that the earth
has a nearly uniform circular motion
around the sun?

The earth moves in a plane around the sun.
Define the geometric shape called a plane.



The earth and a motorcycle need something
in order to turn. What is that?


The Physics of Countersteering







 "What does this picture

tell you about the

speed of these


Nina Prinz and Letizia Marchetti
- Ducati Women's Motorcycle Racing Team



"A large centripetal

(center directed)

force in needed to turn

at high speeds."



Force on an Object Moving in a Circle
Show Me The Physics YouTube Channel




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Show Me The Physics






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Rutgers U.



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School blocks YouTube? Download file below






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Centripetal Velocity

Science Joy Wagon



In order for an object to move at constant speed in a circle, an outside force must constantly turn the object toward the
center of circular path.



Circular Motion, Car on a Banked Track

by Dr. Michael R. Gallis mrg3@psu.edu

Penn State Schuylkill

Go Nittany Lions!!


Instructional Video


Draw the centripetal force,
and tangential velocity




Draw the centripetal force,
and tangential velocity





Draw the centripetal force, and tangential velocity





Where should you

release the ball to hit

the target? 







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At point P, the car hits
an area of ice and loses
all frictional force on its tires.
Which path does the car follow on the ice?


June 2001 Regents








Tangent to
the semi-circle




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