Circular Motion
What happens to the centripetal force if the speed is constant while the radius is tripled?
1/3 its original value
What happens to the centripetal acceleration if the speed is doubled but radius is constant?
4X its original value
What happens to the centripetal force if the speed is tripled but radius is constant?
9X its original value
Radius
A line segment from the center of the circle to a point on the circle; has half the length of the circle's diameter
Diameter
A line segment that connects two points on a circle's circumference and goes through the center; has twice the length of the circle's radius
Centripetal force
A net force directed toward the center of a circle (mv²/r); can be a gravitational force, a tension, an applied force, or a frictional force
Period
The time it takes for an object to make one complete revolution (1/f); unit: seconds
At the top of the circular path of an object, its direction of acceleration is
down (toward the center of the circle)
When an object undergoes uniform circular motion, its acceleration
is not zero; it causes the object to change direction
At the top of the circular path of an object, its direction of velocity is
tangent to the circle
static friction
the force is responsible for keeping a car on an unbanked curve or a coin on a record player
perpendicular
the relationship between the direction of velocity of an object undergoing uniform circular motion and the direction of its acceleration
What happens to the centripetal acceleration if the speed is constant but radius is doubled?
It becomes 1/2 its original value.
Centripetal acceleration
The acceleration of an object undergoing uniform circular motion, which is directed toward the center of a curved or circular path (v²/r); caused by a net centripetal (center-seeking) force
Circumference
The distance around a circle (2πr)
Frequency
The number of revolutions the object makes in one second (1/T); unit: 1/s or Hz
If a car goes around a curve, the direction of its acceleration
toward the center of the circle
Uniform circular motion
when an object moves in a circle and the magnitude of its velocity is not changing, but its direction is constantly changing (accelerating)
