November 9, 2015

Bell Work List 3 examples of devices at school or home that uses gravity directly to do a job. Explain how each device works. (Example a paperweight uses gravity to hold papers in place.) List 3 examples of devices at school or home that uses gravity indirectly to do a job. Explain how each device works. (Example a water faucet over a sink because gravity pulls down on the water.)

Goals To define gravity

Agenda Bell Work New Seats Tomorrow Pretest in Packet II Notes Gravity Movie Lab-Reacting to Gravity Announcement-Common Assessment Review Monday 11/16- 2:40-3:20

Q: What’s Gravity? Gravity is the attraction of one object to another Attraction occurs when molecules of one object pull on molecules of another object Gravity pulls things together, toward the center (it does not act DOWN!)

Q: What kinds of objects have gravity? Anything with mass has gravitational pull/force You have gravity, so why don’t you notice your own gravity? Your gravity is VERY small compared to that of the Earth, so you notice the Earth’s gravity but not your own.

Q: Who discovered gravity? Isaac Newton played a big part (remember his apple falling from a tree?) He probably thought: the apple is speeding up as it moves toward the ground, so there must be a force acting on it (Remember his 2nd law? F = ma) Let’s call the force gravity, and the associated acceleration “acceleration due to gravity”

Q: Who discovered gravity? This force reaches all the way to the moon, keeping the moon in orbit!

Q: Who discovered gravity? Universal Law of Gravitation All objects in universe experience gravitational attraction (hence UNIVERSAL!) Newton is famous for observing the universality of gravity