1. Vectors & Projectile Motion Physics LG Jan. 30, 2009

2. Motion is Relative ► Frame of Reference - perspective from which you observe

3. Truck at Rest If the ball is thrown at 60 km/h relative to the truck, at what velocity will the person catch the ball at?

4. Truck Moving Away ► ► If the ball is thrown at 60 km/h west relative to the truck and the truck moves at 40 km/h east relative to the catcher, at what velocity will the person catch the ball at?

5. Truck Moves Towards ► ► If the ball is thrown at 60 km/h west relative to the truck and the truck moves at 40 km/h west relative to the catcher, at what velocity will the person catch the ball at?

6. ► Scalar - measurement of magnitude only  Ex) mass, volume, speed ► Vector - measurements with both magnitude and direction  Ex) velocity, acceleration, force

7. arrowhead = direction length of arrow = magnitude Vectors

8. Vector addition

9. Resultant – sum of vectors

10. ► Boat crossing river animation… http://www.schulphysik.de/suren/Applets.htm l http://www.schulphysik.de/suren/Applets.htm l

11. Pythagorean Theorem a 2 + b 2 = c 2 a 2 + b 2 = c 2

12. ► c 2 = a 2 + b 2 ► c 2 = 80 2 + 60 2 ► c 2 = 6400 + 3600 ► √c 2 = √10,000 ► c = 100 km/hr

13. Example Problem ► c 2 = a 2 + b 2 ► c 2 = 4 2 + 3 2 ► c 2 = 16 + 9 ► c 2 = 25 ► c = 5 km/h

14. Vector addition ► Pythagorean Theorem - ► Parallelograms - ► Head-to-tail method - ► Trigonometry -

15. Vector Addition http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=51 http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=51

16. What is the vertical and horizontal component of a vector? http://www.batesville.k12.in.us/Physics/APPhyNet/Vectors/Hor_&_Vert_Comps.html

17. Projectile Motion Projectile – an object moving through air affected by gravity Projectile – an object moving through air affected by gravity

18. Projectile Demos ► Shooter/ Dropper ► Monkey and Hunter

19. Projectile Motion Horizontal and vertical motion act independently Horizontal and vertical motion act independently

21. How fast is the ball thrown?

22. ► Vertical ► d=.5at 2 ► 5 =.5(10)t 2 ► t= 1 second ► Horizontal ► v= d/t ► v= 20m/1s ► v= 20 m/s The ball is thrown at 20 m/s!

23. What angle should a ball be kicked to get the farthest? Upwardly-Moving Projectiles

24. Projectiles launched at the same speed but different angles.

25. Shot Put - 45º is not the ideal angle, why? You are already off the ground 1-2 meters.

26. 45º is the ideal angle for high speed projectiles either. Why? 45º is the ideal angle for high speed projectiles either. Why? Air resistance must be considered.

27. Fast Moving Projectiles ► What would happen if you threw a ball so fast that the curvature of the earth came into play?

28. Fast Moving Projectiles ► Satellite- a projectile traveling fast enough to fall around the earth rather than into ► To stay in orbit around the earth, a satellite needs to travel at 8 km/s!

29. Hang Time

30. Due Next Week   POTW   11s Bull’s eye lab   12s Rocket Lab   30s Motion Worksheet #1   31s Motion Worksheet #2   32s Motion Review   Test will be next Thursday Feb 5 th ► ► Study the 1s, 2s, labs, and worksheets ► ► Use the back page of booklet under motion for note sheet for test.