1. King Fahd University of Petroleum & Minerals
Mechanical Engineering
Dynamics ME 201 BY
Dr. Meyassar N. Al-Haddad
Lecture # 26

2. Examples of relative motions “motion of one part lead to the
motion of other parts” (pin-connected rigid body)

3. Relative-Motion Analysis :
Relative Velocity
Instantaneous Center of Zero Velocity
Relative Acceleration

4. Examples of Non-Relative-Motions
)sliding connections and has two independent motion)

5. Position
Rotating axes

6. Rotating axes & translating object
Velocity
Rotating axes & translating object
wr + v

7. Velocity VC = Velocity of the Collar, measured from
the X, Y, Z reference
VO = Velocity of the origin O of the x,y,z reference
measured from the X,Y,Z reference
(VC/O)xyz = relative velocity of “C with respect to O”
observer attached to the rotating x,y,z reference
= angular velocity of the x,y,z reference, measured
from the X,Y,Z reference
rC/O = relative position of “C with respect to O”

8. Rotating axes & translating object
Acceleration
Acceleration is the time derivative of velocity
Rotating axes & translating object
(wr + v)

9. Rotating axes & translating object (wr + v)
Acceleration of origin
Acceleration of the object
w2 r
Normal acceleration
a r
Tangential acceleration
Coriolis acceleration

10. Coriolis acceleration
Whenever a point is moving on a path and the path is rotating, there is an extra component of the acceleration due to coupling between the motion of the point on the path and the rotation of the path. This component is called Coriolis acceleration.
First measured by the French engineer G.C. Coriolis
Important in studying the effect “force and acceleration” of earth
rotation on the rockets and long-range projectiles

12. In a cylindrical coordinate
Rearrange
Compare !

14. Recall – Cylindrical coordinate
Coriolis acceleration

15. Example 16-20

16. Thank You