1. Chapter 7 Rotational Motion & Law of Gravity
Section 7-2
Tangential and Centripetal Acceleration

2. Tangential Speed Objects in circular motion have tangential speed.
Tangential Speed of any point rotating about an axis is instantaneous linear speed of that point.

3. Example: Tangential Speed
Horses on a carousel move at the same angular speed but different tangential speeds.

5. Tangential Speed
Tangential Speed = distance from axis x angular speed.
Vt = r ω
Where r is Radius and ω is instantaneous angular speed (speed at that moment)

6. Practice with Sample 7E
Pg. 255

7. Tangential Acceleration
Tangential Acceleration is tangent to the circular path.
Tangential acceleration = distance from axis x angular acceleration
at = r α
Where r is Radius and α is instantaneous angular acceleration.

8. Practice with Sample 7F
Pg. 256

9. Centripetal Acceleration
‘Center seeking’ acceleration.
Circular motion acceleration is due to change in direction.

10. Example: Centripetal Acceleration
Tangential and Centripetal accelerations are perpendicular.

11. Tangential Vs. Centripetal Acceleration
Tangential and Centripetal accelerations are not the same.
Tangential Component of acceleration is due to changing speed.
Centripetal component of acceleration is due to changing direction.

12. Formula: Centripetal Acceleration
Centripetal Acceleration = (tangential speed)2 / distance from axis
ac = vt2 / r
ac = r ω2

13. Sample Problem 7G
Pg. 258

14. Assignment Practice 7E pg. 255 2-4 Practice 7F pg. 256 2-3
Practice 7G 2-5
Eight problems Total!!