2GravityThe force that pulls objects towards each other – a force of attraction between objects!On Earth, gravity is pulling everything straight down toward the center of the Earth (of course we get stopped by the ground)
3WeightWeight is the force of gravity on a person or object on the surface of a planetWeight depends on mass and the force of gravity at a specific location
4MassThe measurement of the amount of matter “stuff” in an object
5Inertia The tendency of an object to resist a change in its motion Mass changes an object’s inertia – the more mass the more inertia… the object will be harder to start or stop
7The Universal Law of Gravitation The force of gravity acts between all objects in the universe.This means that all objects attract each other!
8Factors Affecting Gravity Mass – the greater the mass the greater the gravitational forceDistance – the smaller the distance, the greater the gravitational force
9with the same amount of force! The Earth and youYou are attracted to the Earth and the Earth is attracted to youYou pull on the Earth and the Earth pulls on you…with the same amount of force!
10FallingWhy when we fall are we pulled down towards the Earth instead of pulling the Earth up towards us?The Earth has a whole lot more mass (more inertia) – needs more force to move!
11Why are we pulled more towards the Earth than the moon? The Earth has more mass and is closer to us!
12Mass and Weight on the Moon Your mass will not change on the moonYour weight will decrease since there is less gravity on the moonThere is less gravity on the moon because the moon is less massive than the Earth
13Weight on other planets Gravity on the other planets depends on the mass of the planet and the radius of the planet