IB Physics 12 Mr. Jean September 23 rd, 2014

The plan: Video clip of the day – 0xshttps:// 0xs Banked turns with Friction Conical Pendulums Investigations returned on Thursday

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

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***)

Universal Gravitational Constant:

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

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

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:

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

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?

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

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

Part #1:

Part #2:

Part #3