1. Physics 11 Advanced Mr. Jean May 1 st, 2012

2. The plan: Video clip of the day Hooke’s Law Spring Potential Energy Power Efficiency Lab Time Chapter #6 Pre-test

3. Hooke’s Law yelled at you http://www.brightstorm.com/science/physic s/oscillatory-motion/hooks-law/http://www.brightstorm.com/science/physic s/oscillatory-motion/hooks-law/

4. Potential Energy Yelled at you: http://www.brightstorm.com/science/physic s/oscillatory-motion/spring-potential- energy/http://www.brightstorm.com/science/physic s/oscillatory-motion/spring-potential- energy/

5. Where is money wasted in Schools?

6. Power: Power is the quotient of work and time. Essentially is the amount of work which gets done in a given time interval.

7. Power QuantitySymbolSI Unit PowerPW (watts) Work doneWJ (joules) Timet s (seconds) EnergyEJ (joules)

8. Efficiency Efficiency is the ratio of useful energy or work output to the total energy or work input. The greater the efficiency, the less “wasting” of energy.

9. Efficiency: W o = Useful output work energy (J) W i = Input energy (J) Efficiency has no unit. It is a ratio and units cancel in ratios! (But you already know this….)

10. Efficiency Alternative Definition: E o = Useful output energy (J) E i = Input energy (J) Same deal as before with units and efficiency.

11. See Formula Sheet: Talk about applications

12. To do: Finish Pendulum Lab Work on Chapter #6 Pre-test