8/26/16 Friday Get your folders on your way into class! Get a copy of the “Great Gravity Escape” data sheet off of the white shelf, below the overhead. Take a few minutes to answer the questions the best you can. Remember to think about the data we collected during yesterday’s activity. Turn this in to your tray before you leave.

8/26/16 Friday Get a copy of the guided notes off of the white shelf below the overhead. A couple of classes may already have a copy of this in your folders. Use the following power point to fill in the notes. Put these in your folders. Be sure to put your folders back up before you leave.

8/29/16 Monday Bellringer Would a ball with a different mass escape earth’s gravity sooner/later? Explain

8/30/16 Tuesday Bellringer In a weightless environment in space, is there any gravity acting on an astronaut? Why or why not?

Gravity Earth Space

Gravity The force of attraction that exists between all matter in the universe. Key word is matter Matter is the stuff you are and everything else is made of It takes a lot of mass for the gravity to be noticeable. Like planetary mass

Law of Gravity The force of attraction between any two objects depends on their masses and the distances between them. The bigger the object, the more gravity it has The closer an object is to something the stronger the pull.

Mass Mass is how much matter is in something. It is measured using grams and kilograms It is NOT the same as weight

Distance Gravity’s force depends on how close the object is to something. As an object gets further away, the force of gravity on that object decreases Inverse square law As the distance increases the gravity decreases exponentially Class demonstration

1 Gravitational force = Distance squared 1 G force = d2

Weight, Mass, and Gravity Weight and Mass are not the same thing!!! The are related though Weight is your mass being pulled down by gravity Gravity on earth pulls us down at 9.8 m/s2

Weight, Mass, and Gravity How much matter you are made of Does not change depending location It is the same if you are on earth or in space or on the moon Weight The relationship between mass and gravity Changes depending on location Is different on earth and the moon and space

In the absence of air resistance, all things will fall toward the earth at the same velocity Weight = mass x free-fall acceleration w= m g

Find Your Mass We can find out how much mass we have by using the previous formula W = mg Weight is in Newtons, so convert your lbs to N. Multiply lbs times 4.448 Then divide by gravity

Gravity on Earth Gravity pulls us down toward the center of the earth. At different parts of the earth there is more matter between the surface and the center. The Poles are flatter and the equator bulges The bulge means there is more gravity at the equator People weigh more at the equator than the poles.

Gravity & the Moon Newton observed the Moon’s motion and realized that its direction changes because of the gravitational attraction of Earth The Moon is constantly falling toward Earth If no gravity, the Moon would continue to move in a straight line and would not orbit Earth The same is true of the planets and their moons, stars, and all orbiting bodies throughout the universe.