1. (law of inertia) Newton’s First Law

3. What is Inertia??? INERTIA is a property of an object that describes how hard it is to change its motion INERTIA is a property of an object that describes how hard it is to change its motion more mass = more inertia more mass = more inertia

4. Newton’s First Law (law of inertia) An object at rest will continue to stay at rest unless an outside force acts on it and …

5. Newton’s First Law (law of inertia) an object in motion will continue to stay in motion at constant speed in a straight line unless an outside force acts on it

6. FORCE is a push or a pull applied to an object that will cause it to start moving, stop moving or change its speed or direction FORCE is a push or a pull applied to an object that will cause it to start moving, stop moving or change its speed or direction What exactly is a force???

7. ??? What are some examples of outside forces that would act on objects???

8. FRICTION is the force that acts in the opposite direction of the motion of the object FRICTION is the force that acts in the opposite direction of the motion of the object (A cart will roll until friction stops it) Friction

9. Gravity Gravity is a force of attraction between 2 objects Gravity is a force of attraction between 2 objects Everything has gravity, but it is not felt unless the objects are very big! (Like planet-sized big!) Everything has gravity, but it is not felt unless the objects are very big! (Like planet-sized big!) On EARTH gravity = 9.8 m/s 2 On EARTH gravity = 9.8 m/s 2 On other planets it is different! On other planets it is different! In space it is ZERO!!! In space it is ZERO!!! (a ball that’s thrown will travel out from your hand until gravity pulls it to the ground)

10. How Gravity Affects Your Mass MASS is the measure of the amount of matter in an object MASS is the measure of the amount of matter in an object –measured in grams (g) or kilograms (kg) WEIGHT is a measure of the force of gravity on the mass of an object WEIGHT is a measure of the force of gravity on the mass of an object –measured in Newtons (N) (NOT POUNDS!) Weight = Mass x Gravity