1. Physics 1-3-08 Introduction of momentum

2. What will be done the next two weeks We will be discussing the concept of Momentum until Wednesday of next week Next Thursday/Friday will be spent on review for test Find your old tests, use as a basis for studying.

3. New Year  New Books (almost) We have new books, but are one short If somebody is absent, or If I have 2 that really want to share Have asked for another book…

4. Those getting books Enter book #, (if it has not already been done) Write name and year in front Sign list, for teacher

5. Question What would you rather get hit with? A bowling Ball or a steel ball bearing?

6. On what does your answer Depend?

7. Momentum Multiply the two factors together and you can begin to quantify the risk in being hit by the object The name of the value is called momentum

8. Momentum “Pain upon impact” “Inertia in motion” Quantity of motion found by multiplying an objects mass by its velocity It is a vector value (Magnitude and Direction) Units Kg m/s

9. What does not have momentum?

10. What has more momentum? The statue of liberty or a SUV moving at 60 mph done the road?

11. How can one change momentum? Examples of objects changing their momentum

12. Impulse The measure of a change in momentum Any change in momentum requires a net force Any application of a net force, results in a change of momentum of the object

13. What is Newton’s second law?

14. To find the impulse of an object Fnet Δt = m Δ v = impulse

15. Car Crashes Why do some people survive and others do not?

16. Important For a given crash, the impulse is constant regardless of how the crash occurs Impulse = mΔv

17. Time and force The length of time it takes for the crash to be complete determines the amount of force applied during the crash Seat belts Foam padding Air Bags Crumple zones

18. Change of momentum and Sports Baseball/ softball Golf

19. Homework New Book! Page 233 Problems 1-5