Earth’s Place in the Universe Vocabulary Unit 2 Tuesday HW - 9/26 Matter - Anything that takes up space and has mass. Mass - A measure of the amount of matter in an object. (unit = grams) Weight - A measure of the force of gravity on an object. (unit = Newtons) Force - A push or a pull. Gravity - A force that attracts all objects to each other. Thursday HW - 9/28 Law of Universal Gravitation - Every object in the universe attracts to every other object. Gravitational force is only noticeable when one or both of the objects has a very large mass. Inertia - The tendency of an object to resist a change in motion. Objects want to keep on doing what they are doing. Newton’s First Law of Motion - An object in motion will stay in motion and an object at rest (not moving) will stay at rest until a force changes it.
