EQ: How is the Earth different from the other planets in our solar system? Solar System Gravity

Forces Gravity is a force A force is a push or a pull Newton’s Third Law of Motion states that forces act in equal but opposite pairs. Forces can be described in two ways Balanced forces Two or more forces equally and oppositely exerted on each other cancel each other out and will not change an object’s motion. Unbalanced Forces If one force is stronger than another force , the object will move.

Gravity Gravity or gravitational forces are forces of attraction. We're not talking about finding someone really cute and adorable. It's like the Earth pulling on you and keeping you on the ground. That pull is gravity at work.

Gravity and Mass Every object in the universe that has mass exerts a gravitational pull, or force, on every other mass. The size of the pull depends on the masses of the objects. Mass= the amount of matter in an object

A gravitational pull You exert a gravitational force on the people around you, but that force isn't very strong, since people aren't very massive. When you look at really large masses, like the Earth and Moon, the gravitational pull becomes very impressive

Gravity The gravitational force between the Earth and the molecules of gas in the atmosphere is strong enough to hold the atmosphere close to our surface. Smaller planets, that have less mass, may not be able to hold an atmosphere.

The Sun’s Pull Obviously, gravity is very important on Earth. The Sun's gravitational pull keeps our planet orbiting the Sun. The Sun’s gravitational pull also keeps the other planets in our solar system in its orbit.

Other Planets But the force of gravity is not the same on all planets! Some planets, like Mercury have less of a gravitational pull. While others, like Neptune, have a stronger force.

Gravity, Mass and Weight Many people incorrectly assume that mass and weight is the same thing. It’s not! Mass is the amount of matter in an object (or person) Weight is the gravitational force on that mass.

Weighing in on other planets Because the gravitational force is different on each planet, your weight changes from planet to planet. Sometimes you will weigh more, sometimes less, depending on where you are in our solar system.

Today Look at your sheet. Look at the gravitational pull on each planet Which planet has the greatest pull? Which planet has the weakest pull? Which planet’s gravitational force is the most similar to Earth’s? You were weighed on your way in to class today. Write your weight at the top of the page.

Today You will use that weight to figure out your weight on each planet of our solar system. Example: 120lbs on Earth Mercury: 120X .38=45.6 lbs Use your weight for each of the planets. Then use the same method to figure out what a 300 lb football player would weigh on each planet.