1. Newton’s Laws of Motion

2. Force A force is a push or a pull. Net force refers to what you get when you consider the total effect of all the forces acting on an object. If the forces on an object are equal and opposite, they are said to be balanced, and the object experiences no change in motion. If the forces are not equal and opposite, then the forces are unbalanced and the motion of the object changes.

3. Acceleration Acceleration is any change in speed and/or direction (a change in velocity) over some period of time. A net force acting on an object causes it to accelerate. Object accelerates

4. Inertia It’s hard to change the motion of an object that has lots of inertia & it’s easy to change the motion of an object that has little inertia. Mass can be defined as the measure of an object’s inertia. The more mass an object has, the more inertia it has, and the harder it is to change its motion.

5. Applying a larger net force to an object results in a larger acceleration. A soccer ball sitting at rest takes an unbalanced force of a kick to change its motion.

6. small forcesmall acceleration leads to large forcelarge acceleration leads to

7. If you apply equal net forces to two objects, the one with the smaller mass will accelerate more.

8. small masslarge acceleration leads to large masssmall acceleration leads to

9. If you want to cause two different objects to have the same acceleration, the object with the larger mass will require a larger force.

10. small forcesame acceleration can lead to large forcesame acceleration can lead to

11. Newton’s 2 nd net force acting on an object = mass of object acceleration of object F = ma Those three letters, plus the equals sign, are a statement of Newton’s 2 nd Law of Motion.

12. Newton’s 3 rd Law of Motion

13. Imagine you are in a football game. You line up facing your opponent, the ball’s snapped, and the two of you crash together. Who feels the force of the crash?

14. Action & Reaction Newton was the first to realize that all forces occur in pairs. –There is no such thing as an isolated force existing by itself! Right now, gravity is pulling you down in your seat, but Newton’s 3 rd Law says your seat is pushing up against you with equal force. You are not moving because there is a balanced force acting on you. –Gravity is pulling down, your seat is pushing up.

15. Newton’s 3 rd Law Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. Simply put – –For every action (force) there is an equal, but opposite, reaction.

16. Review Newton’s 1 st – –Inertia- an object will resist a change in its motion. (If not moving, it doesn’t want to move. If moving, it wants to keep moving in a straight line at a constant speed.) Newton’s 2 nd – –F = ma –force is equal to mass times acceleration Newton’s 3 rd – –For every action there is an equal and opposite reaction.