AP Modules 3-2 and 3-3

Modules 3-2 and 3-3

Uniform Circular Motion

Uniform Circular Motion

• Motion with a constant linear speed around a circle, tangent to the path.

• Velocity is changing because direction changes at each point along the circle.

• Acceleration is pointing towards the center of rotation.

Centripetal Force

• Newton's Second Law tells us that if an object is experiencing an acceleration, there is an unbalanced Net Force acting in the same direction.

• Centripetal Force also points towards the center of the circle.

• Centripetal Force is a description for a force that causes circular motion.

Period and Frequency

• Period (T) is the time it takes for one cycle to occur.

• Frequency (f) is the number of cycles that occur per second.

• These are inverse of one another.

Multiple Choice

When an object is in circular motion it is constantly changing its velocity.

• True
• False

Multiple Choice

An object moving is moving with uniform speed in a horizontal counterclockwise circle. At the location depicted, the centripetal force stops. Which path will the object follow?

Multiple Choice

A racecar is driving with a constant speed around a track (depicted). At what location will the car have the least centripetal force acting on it?

• b

• C

• D

• F

Multiple Choice

Which statement is true about an object that is traveling in uniform circular motion?

• The speed of the object varies.

• The net force on the object is directed toward the center of the circular path.

• The direction of the object's velocity is constant.

• The net force on the object is directed away from the center of the circular path.

Multiple Choice

Two students (A and B) are on a merry-go round (depicted). Which student has a greater tangential speed?

• A

• B

• Both are equal

• Cannot be determined

Multiple Choice

Two students (A and B) are on a merry-go round (depicted). Which student has the greater period of revolution?

• A

• B

• Both are equal

• Cannot be determined

Multiple Choice

An object is moving with uniform speed in a horizontal, counterclockwise circle. At location D, which way does the centripetal force vector point?

• Left

• Right

• Up

• Down

Multiple Choice

What is the direction of the velocity at point B, if the ball is revolving clockwise?

• up
• right
• down
• left

Multiple Choice

A particle P is moving in a circle with uniform speed. Which one of the following diagrams correctly shows the direction of the acceleration a and velocity v of the particle at one instant of time?

• A

• B

• C

• D

Multiple Choice

You swing a bucket of water attached to a string in a circle above your head. What keeps the water in the bucket?

• Friction

• Centripetal Force

• Gravity

• Inertia

Poll

How confident do you feel about the material from Modules 3-2 and 3-3?

• Very confident. I understand this material well!

• I understand most of it, but there are some things I need to study.

• Neutral. I understand some of it, but I need to review quite a bit.

• Overall, I am more confused than confident. I need to review a lot more.

• I am totally lost. I do not understand any of this material.