1. ENGR 215 ~ Dynamics Sections 15.4

2. Central Impact

4. Restitution Derivation

5. Restitution Elastic Impact (e=1) Plastic Impact (e=0)

6. Central Impact Analysis Conservation of momentum Coefficient of Restitution

7. Lecture Example 1: Determine the restitution of a “super” ball when dropped from a height near 1 m.

8. Oblique Impact

9. Oblique Impact Analysis Conservation of momentum for the system of particles along the line of impact. Coefficient of restitution relates the velocity components of the particles along the line of impact. Conservation of momentum for each particle in the direction perpendicular to the line of impact.

10. Lecture Example 2: A “super” ball is rolled down a ramp off the end of the table. Determine the location of the ball on the third bounce.

11. Lecture Example 3: Disks A and B have a mass of 15 kg and 10 kg, respectively. If they are sliding on a smooth horizontal plane with the velocities shown, determine their speeds just after impact. The coefficient of restitution between them is e = 0.8.