1. IB Physics 12 Mr. Jean September 23 rd, 2014

2. The plan: Video clip of the day –https://www.youtube.com/watch?v=QcdlGjAP 0xshttps://www.youtube.com/watch?v=QcdlGjAP 0xs Banked turns with Friction Conical Pendulums Investigations returned on Thursday

3. Chapter #5 If you are wondering where we are: Giancoli –P. 117 to 122  Gravitational Constant –P. 122 to 127  Newton & Kepler’s Synthesis

5. Newton’s Law of Universal Gravitation: F g = force of gravity in newtons (N) m 1 = first mass in kilograms (Kg) m 2 = second mass in kilograms (Kg) r = distance between centers of mass in meters G = Universal Gravity Constant (***next slide for units***)

6. Universal Gravitational Constant:

7. Kepler’s First Law: Planets move in elliptical orbits around the sun. As an average these orbits are nearly circular.

8. Kepler’s Second Law: An imaginary line between the Sun and a planet sweeps out equal areas in equal time intervals.

9. K = is a CONSTANT for all planet’s as they travel around the sun. r = average distance from sun (m) T = period of planet’s revolution around the sun (seconds) Kepler’s Third Law:

11. Satellites in space: A satellite in space moves around a heavy body. To keep the satellite from smashing back into the Earth (or planet it is orbiting), scientists set the force of gravity equal to the centripetal force. F g = F c

12. Example Question: You find yourself in space. In fact you are walking on a large asteroid. Your mass is 70kg, the asteroid has a mass of 8.0 x 10 5 kg and the radius between the two centers of mass is 80 meters. What is your weight on the asteroid?

13. m 1 = 70 (kg) m 2 = 8.0 x 10 5 (kg) r = 80 meters (m)

17. Planetary Information Sheets: Complete the first 4 for each sheet. –Mercury –Venus –Earth –Mars

18. Part #1:

19. Part #2:

20. Part #3