1. Based on your knowledge and everything we have seen in this class, How would you relate Thanksgiving to Physics?

3.  https://www.youtube.com/watch?v=31MMw3E azqw&list=PLajRX1HxHcZNgivoEWVPDMWb5h GLCNrB6 https://www.youtube.com/watch?v=31MMw3E azqw&list=PLajRX1HxHcZNgivoEWVPDMWb5h GLCNrB6

4. Uniform circular motion is motion along a circular path in which there is no change in speed, only a change in direction. Constant force Fc toward center. Constant velocity V tangent to path. v FcFc Question: Is there an outward force on the ball?

5. The question of an outward force can be resolved by asking what happens when the string breaks! When central force is removed, ball continues in straight line. v Ball moves tangent to path, NOT outward as might be expected. Centripetal force is needed to change direction.

6. The direction of the velocity vector at any instant is in the direction of a tangent line drawn to the circle at the object's location. (A tangent line is a line that touches a circle at one point but does not intersect it.)

7.  What is Centripetal Force? A force that acts on a body moving in a circular path and is directed toward the center around which the body is moving.

8.  Where is Centripetal Force pointed towards?  What is this Force called? Gravitational Force

9.  Car going around a curve. You are sitting on the seat next to the outside door. What is the direction of the resultant force on you as you turn? Is it away from center or toward center of the turn? Force ON you is toward the center. FcFc

10. There is an outward force, but it does not act ON you. It is the reaction force exerted BY you ON the door. It affects only the door. The centripetal force is exerted BY the door ON you. (Centrally) FcFc F’Reaction

11. BELL RINGER! DO NOT COPY THE QUESTIONS! Draw the circle from the right with the respective vector from the bottom based on each question. 1. Which vector below represents the direction of the force vector when the object is located at point A on the circle? 2. Which vector below represents the direction of the force vector when the object is located at point C on the circle? 3. Which vector below represents the direction of the velocity vector when the object is located at point B on the circle? 4. Which vector below represents the direction of the velocity vector when the object is located at point C on the circle?

12. http://science360.gov/obj/tkn-video/5f385cf5- 5046-4279-984e-27f911c6ca07

13.  1. Explain the different forces a race car experiences while it is going in speeds in excess of 200 mph. around a turn. Include a picture with these different forces.

14.  In your own words, explain centripetal motion and provide an example.

15.  Where is the Centripetal Force pointed towards?  What is this force called?

16. PAP vfvf ac =ac = vtvt Definition: = vtvt v2Rv2R a c = Centripetal acceleration:

17. R v m a c = 12.8 m/s 2 m = 3 kg F = (3 kg)(12.8 m/s 2 ) F c = 38.4 N F c = 38.4 N A 3-kg rock swings in a circle of radius 5 m. If its constant speed is 8 m/s, what is the centripetal acceleration? R = 5 m v = 8 m/s What is the Force (F)? a c = 12.8 m/s 2

18. 450 N 30 m v = 15 m/s R FcFc m=? Speed skater  F = mv 2 /R  FR = mv 2  FR/v 2 = m,  Substitute m=(450N)(30m)/(15m/s) 2 Solve for mass(m) m=60 kg

19. R v v Resultant force toward center F c = mv 2 R Consider TOP of circle: AT TOP: T mg T + mg + T = mv 2 R T = - mg mv 2 R

20. R v v Resultant force toward center F c = mv 2 R Consider bottom of circle: AT Bottom: T mg + T - mg = mv 2 R T = + mg mv 2 R T mg

21. R v v AT TOP: T mg + AT BOTTOM: T mg + T = - mg mv 2 R T = + mg mv 2 R

22. R v v T mg mg + T = mv 2 R At Top: T = - mg mv 2 R T = 25 N - 19.6 N T = 5.40 N A 2-kg rock swings in a vertical circle of radius 8 m. The speed of the rock as it passes its highest point is 10 m/s. What is tension T in rope?

23. R v v T mg T - mg = mv 2 R At Bottom: T = + mg mv 2 R T = 25 N + 19.6 N T = 44.6 N A 2-kg rock swings in a vertical circle of radius 8 m. The speed of the rock as it passes its lowest point is 10 m/s. What is tension T in rope?