1. 7.2 Angular & Linear Speed

2. Angular & Linear Speed
Object moves in circular path, 2 speeds involved
- rate of distance traveled
- rate object center of circle
(linear) s
(angular)
Linear speed:
t = time
 radians r
Angular speed:

3. Angular & Linear Speed Linear speed: Angular speed: Arc length:
 Relates linear & angular speed

4. Get rid of all units on top to get “radians”
(radians don’t have units)
Example 1
Linear speed
A car has wheels that are 28 inches in diameter & is traveling at 45 mph. Find angular speed in radians per minute.
Diameter = 28
Radius = ½(28)
= 14
Linear speed
Angular speed
Convert to radians per minute

5. Homework
#711 Pg , 46, 49, 50, 51 Pg – 7 all