Lecture 7 Flashcards
What is an axis of rotation
A fixed line about which a body rotates
Clockwise rotations are….
Counterclockwise rotations are….
Negative
Positive
Angular position is
The units of this are
How far a body is rotated from its reference
Degrees
Radians
What is Radian
The ratio between an arc length (s) and the radius (r)
Radian = s/r
What is the equation of 1 radian
180 degree
___________
Pie
What is 1 radian
Measure of the central angle whose arc length equals the radius of the circle (s=r)
How do you convert degree to radian
Multiply the number of degrees by 3.14 / 180
How do you convert radian to degree
180 / 3.14
What is angular displacement
Change in angular position between two time periods of interest
Angular velocity is
What is its symbol
What is its unit
What should you make sure
How fast a body is rotating in a particular direction
w = change in angular position
_____________________
Delta time
Unit: Degree/sec or rad/sec
MAKE SURE unit is rad/sec before multiplying by another quantity
Angular acceleration is
What is the formula
What is the unit
The time rate of change in angular velocity
How quickly the object is speeding up or slowing down its rotation in a particular direction
a = delta in angular velocity
___________________
Delta time
Unit: degree/sec^2 or rad/sec^2
What is the arc length of a circle
The distance between the two points along a section of curve
S = The angle x radius
What is the tangential velocity
The direction of the velocity vector is perpendicular to the radial axis and the direction of motion
v = radius x angular velocity
