1. A Question of Bounces COLLISIONS AND MOMENTUM: PROVING FORCES ARE ALWAYS EQUAL

2. For A Question of Bounces Part 1, Did your group have more or less error in their experiment compared to the class? ENTRY TASK:

3.  Complete A Question of Bounces Part 1 Conceptual Physics  Answer Review Questions 1-10 pages 100-101  Plug & Chug Q’s 19 & 20  Think & Explain 23-24 HAVE OUT

4. Challenge: Will the collision force be equal even when the initial positions are of our own choosing? OR Can we achieve an even lower % Error in our experiment? A QUESTION OF BOUNCES PART 2

5. Initial Position (-V i ) Data for Repound Positions (V f )Calculations Gp 1Gp 2Gp 3Gp 4Gp 5Avg Bounce (V f ) V final V initial ∆V (V f -V i ) EXPERIMENT #2: TWO BALLS OF EQUAL MASS & VELOCITY OF OUR CHOOSING

6. F 1 on 2 = (m * ∆v) / t F = force of ball 1 on ball 2 m = mass of ball 1 ∆v = change in velocity of ball 1 t = time needed to change velocity CALCULATING FORCE (BALL 1) Mass of ball 1Average Mass Ball 1 Gp 1Gp 2Gp 3Gp 4Gp 5 Calculations

7. F 2 on 1 = (m * ∆v) / t F = force of ball 2 on ball 1 m = mass of ball 2 ∆v = change in velocity of ball 2 t = time needed to change velocity CALCULATING FORCE (BALL 2) Mass of ball 2Average Mass Ball 2 Gp 1Gp 2Gp 3Gp 4Gp 5 Calculations

8. HOW DO THE FORCES EXPERIENCED BY THE TWO BALLS COMPARE?

9. HOW DO THE FORCES CHANGE WHEN THE VELOCITY OF THE BALLS INCREASES?

10. (Expected Value – Actual Value) Expected Value CALCULATING PERCENT ERROR X 100

11. Initial Position (-V i ) Data for Repound Positions (V f )Calculations Gp 1Gp 2Gp 3Gp 4Gp 5Avg Bounce (V f ) V final V initial ∆V (V f -V i ) EXPERIMENT #3: TWO BALLS OF DIFFERENT MASS & VELOCITY FROM 1 ST EXPERIMENT

12. F 1 on 2 = (m * ∆v) / t F = force of ball 1 on ball 2 m = mass of ball 1 ∆v = change in velocity of ball 1 t = time needed to change velocity CALCULATING FORCE (BALL 1) Mass of ball 1Average Mass Ball 1 Gp 1Gp 2Gp 3Gp 4Gp 5 Calculations

13. F 2 on 1 = (m * ∆v) / t F = force of ball 2 on ball 1 m = mass of ball 2 ∆v = change in velocity of ball 2 t = time needed to change velocity CALCULATING FORCE (BALL 2) Mass of ball 2Average Mass Ball 2 Gp 1Gp 2Gp 3Gp 4Gp 5 Calculations

14. HOW DO THE FORCES EXPERIENCED BY THE TWO BALLS COMPARE?

15. (Expected Value – Actual Value) Expected Value CALCULATING PERCENT ERROR X 100

16.  Make an appointment to meet with Ms. KL to discuss Science Fair Assignment #1  Revise  Speed Bumps Conclusions  Safe Landings Conclusions  Science Fair Assignment #1 HOMEWORK: