1. Physics 11 Advanced Mr. Jean April 25 th, 2012

2. The plan: Video clip of the day Rube Goldberg Reminder Grade 10 Science Review Investigation 6A Kinetic Energy Review sheet

3. Do not forget! Rube Goldberg Project –Approximately 10% of grade. Science Fair Project –Approximately 10% of grade.

4. RGB: Real meets digital.

5. Review from Grade 10: Thermal Energy Formula: Q = mc∆T Q = Amount of thermal energy (J) m = mass in grams (g) c = Specific heat capacity (J / g) T = Temperature change (ºC)

6. James Joule, 1818-1889 Image credit: Wikipedia

8. Temperature Scales: What is a thermometer?

9. Thermometers measure temperature. The first known accurate thermometer was invented about 350 years ago.

11. Triple Boiling Point of water

12. The point of thermal dynamics (Study of “heat” energy) is really to do work. We know that heat is really a form of motion in particles and this motion can be used to produce energy.

13. Heat Engine Concept Any time a temperature difference exists between two bodies, there is a potential for heat flow Examples: –heat flows out of a hot pot of soup –heat flows into a cold drink –heat flows from the hot sand into your feet Rate of heat flow depends on nature of contact and thermal conductivity of materials If we’re clever, we can channel some of this flow of energy into mechanical work

14. Heat  Work We can see examples of heat energy producing other types of energy –Air over a hot car roof is lofted, gaining kinetic energy –That same air also gains gravitational potential energy –All of our wind is driven by temperature differences –We already know about radiative heat energy transfer –Our electricity generation thrives on temperature differences: no steam would circulate if everything was at the same temperature

15. How much work can be extracted from heat? ThTh QhQh QcQc  W =  Q h –  Q c TcTc Hot source of energy Cold sink of energy heat energy delivered from source heat energy delivered to sink externally delivered work: efficiency = =  W work done  Q h heat supplied conservation of energy Q

16. Let’s crank up the efficiency ThTh QhQh QcQc  W =  Q h –  Q c TcTc efficiency = =  W work done  Q h heat supplied Let’s extract a lot of work, and deliver very little heat to the sink In fact, let’s demand 100% efficiency by sending no heat to the sink: all converted to useful work

17. Heat Energy: Julius Sumner Miller –Part #1 & #2

18. Investigation 6A Complete the tables Complete the graphs Groups who did not finish all observations you must complete them in the next 30 minutes.

19. What to do: 1) Complete Spring constant lab 2) Complete Kinetic Review Sheet 3) Complete Work & energy Problem 4) Work on Rube Goldberg 5) Work on Science Fair

21. What is to be passed in: 1) Completed tables for three different springs 2) Analyze and Conclude questions 1 and 2 for each spring –Be sure to have: All labels Accurate measurements, units and labelling Very readable graphs!

22. To do: 1) Complete Spring Lab –Pass in quality for Tomorrow period #2. –No title page required. 2) Questions on Kinetic Energy worksheet –Due Thursday morning.