Rotational Motion Flashcards
Equation: Uniform Circular Motion
v = 2 * π * r / T
Note: essentially (distance / time)
T = period
time required for an object to travel once around the circle
time required for a wave to make one complete cycle (inverse of frequency)
Period (T)
Equation: Circumference of a circle
2 * π * r
The ______ vector is constantly changing direction and is tangent to the circle of motion
velocity vector (Object is accelerating even if magnitude of velocity stays the same b/c it is always changing direction)
Acceleration is always pointed to the _____________ of the circle.
inside of the circle
The Velocity vecotr in uniform circular motion is constantly changing direction and is ______ to the circle of motion
tangent
Equation: Centripetal Force
F(c) = m * v^2 / r
What provides the centripetal force for an object of mass (m) being twirled at the end of a string?
F(tension) on the string creates the Centripetal force
Equation: Time for a mass in centripetal motion to make one revolution
t = 2 * π * r / v
2 typical uses for Centripetal force equation
find the velocity given the force
find the force required to sustain uniform circular motion given a certain velocity
Equation: Centripetal acceleration
a(c) = v^2 / r
The acceleration vector in centripetal acceleration always points toward the ______ and constantly changes direction as the object moves.
center of the circle
Equation: Centripetal Force
F(c) = m * v^2 / r
Equation: Torque
Torque = F * L
Note: F = magnitude of force
L = lever arm
SI Unit: N * m
Torque is positive if it tends to produce a _______ rotation about the axis.
counterclockwise
Torque is negative if it tends to produce a ____________ rotation about the axis
clockwise
distance from the axis of rotation to where the force acts on the object at 90º
level arm (L)
for objects that are of uniform density, the__________ is at the geometric center of the object. For objects that are of nonuniform density, the _______ shifts toward the region where most of the mass is concentrated.
center of gravity
also called center of mass
