1. Physics 11
Mr. Jean
May 9th, 2012

2. The plan: Video clip of the day Cold Fusion Pendulum Lab
Physics of Toys Part #2
Complex Collisions

3. Cold Fusion?

4. Pendulum Lab:

5. Lab Stuff:

6. Julius Sumner Miller:
Physics of toys part #2

7. Glancing Collisions:
Glancing collisions: This type of collision takes place in two dimensions. Collisions on a pool table are good examples of this type of collision. Momentum still has to be conserved – it’s the law for crying out loud!
But the problems can become fairly complex. One technique to keep track of what’s going on is to break things into x and y components:

8. Momentum is still conserved:

9. Glancing collisions:
We will deal with greatly simplified collisions. Basically with right angles and one of the bodies at rest at the beginning.
Example: An 8.00 kg mass moving east at 15.0 m/s strikes a 10.0 kg mass that is at rest. The 8.00 kg mass ends up going south at 4.00 m/s.
(a) What is the velocity of the second ball?

10. Billiard Ball Collisions:

11. a) We analyze the momentum in the x and y directions.
The x direction:
This is because the second body has no initial velocity so it has no initial momentum in either the x or y direction.
After the collision, the first body has momentum only in the y direction, so the x direction momentum after the collision involves only the second body.

13. Now let’s look at the y direction:
The first body’s initial motion is only in the x direction, therefore it has no initial momentum in the y direction. The second body is at rest at the beginning so the total initial y direction momentum is zero.

14. Y-component:
Now we can solve for the velocity of the second body using the Pythagorean theorem

15. So ball #2’s total velocity:
Now we find the angle :
Trigonometry is just the thing to find the old angle:

16. To do: Order of importance: Questions from Text Work on Science Fair
Presentations begin May 24 & 25th
Work on Chapter #7 Review Sheet
Practice these questions
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