1. 10.18.10 Pendulum Introduction and Equation Notebook, equation sheets, calculator Please Place Papers in the bin. If absent write dates on top Hooke’s Law QuizRedo by Friday Hooke’s Dry LabLate -50% ONLY Rewrite if NY Reaction time lab Late -50% All other tests and quizzes ONLY Retake if NY All other LabsLate -50% ONLY Rewrite if NY See How They Run late -50% Barbie and Ken Lab late -10% if absent write dates (STAPLE EC ON BACK OF LAB)

2. Oscillations for Pendulums only Length of the pendulum and gravity determine how fast the pendulum oscillates back and forth.

3. Oscillations for Pendulums

4. http://www.worsleyschool.com/ The ride acts like a giant pendulum, with you on the end. Note: the giant Pendulum Swing is attached at the 2 points indicated by the arrows The rider is released from a platform on this pole

5. The Simple Pendulum the dark blue circle shows the Equilibrium position

6. Equilibrium

7. Describe the Speeds ???? Fastest?? Slowest?? Stopped??

8. about arms or legs We can view arms or legs as pendulums, then use an equation to find an answer or if needed give a general description.

9. Try this!! How does it work to run fast without bending your elbows. Try running fast and keeping your arms straight.

10. Try this!! Could you go as fast? Did you have trouble balancing?? If you did not have trouble balancing, was it A LOT MORE WORK? Why??

11. http://phet.colorado.edu/sims/pendulu m-lab/pendulum-lab_en.html

13. Problem: At the California Academy of Sciences the length of the pendulum is: 90.m = L The acceleration of gravity at this location is: 9.8 m/s/s = g (know) What is the Period? T=???? seconds

14. Solution List: L = 90.m g = 9.8 m/s/s T=???? seconds Choose equation: Solve: “Plug and Chug” 90. m 9.8 m/s/s 9.18 s 2 (3.03 s ) (19. s )

15. Why are the items green on this problem?? Pendulum is not a variable, why is it marked?? A.) A simple pendulum has a period of 2.400 seconds where "g" = 9.810 m/s/s. Find the length. B.) Find "g" where the period of the same pendulum is 2.410 seconds at a different location.

16. 1 st find the Length A simple pendulum has a period of 2.400 seconds where "g" = 9.810 m/s/s. T 2 =4π 2 (L/g) 2.400 2 = 4 π 2 (L/9.810) 2.400 2 = 39.44 (L/9.810) 2.400 2 (9.810)= L 39.44 L=1.433 m List: L = ??m g = 9.810 m/s/s T=2.400 S. Equation?

17. Use Length from 1 st part of problem NOW: Find "g" where the period of the pendulum is 2.410 seconds. T 2 =4π 2 (L/g) 2.410 2 = 4 π 2 (1.433/g) 2.410 2 =39.44 (1.433/g) g (2.410 2 )=39.44 (1.433) g =39.44 (1.433)/ (2.410 2 ) g = 9.73 m/s/s List: L = 1.433 m g = ??m/s/s T=2.410 S. Equation?