Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.

##
Rotational Kinematics

- The motion of objects as they
**translate** -- move
bodily from one place to another -- follows a simple
set of rules.
It turns out that a very similar set of rules describes
the motion of objects as the **rotate** -- spin
around in place.
- Physicists usually don't use degrees as a unit to measure
angles; instead, they use
**radians**, which are
ratios of the arc length described by an angle to the
radius of the arc:
length of arc
angle in radians = ---------------
radius

There are 2*pi = 6.28 radians in one full revolution.
Therefore
2 * pi radians = 360 degrees
--> 1 radian = 57.3 degrees

- Each translational quantity has a rotational analog:
displacement (meters) --> angular displacement (radians)
velocity (meter/sec) --> angular velocity (radian/sec)
acceleration (meter/sec^2) --> angular acceleraion (radian/sec^2)

- These rotational quantities obey a set of kinematic equations,
exactly analogous to the 1-D translational kinematic equations.

Viewgraphs
Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.