Motion and Forces

1. Motion and Forces Section 2.3 https://encrypted-tbn2.google.com/images?q=tbn:ANd9GcRIqV4S067Cdm5Ih3vNu-F1_CNdGaLLL-ndzId4zaxoY9XYvhrx

2. State Standard: • PS 5.7:Explain the motion of objects on the basis of Newton’s three Law’s of motion

3. What is a Force? • Force – push or pull one body exerts on another • The ability to change an object's motion by: • Starting • Stopping • Speeding up • Slowing down • Changing direction • May change an object's shape • Net force – the combining of forces when two or more forces act on an object

5. Balanced forces – forces that are equal in size and opposite in direction • Forces are acting on the same object • Do not cause the motion of object to change Forces are vector quantities!

6. Unbalanced forces– forces that are not equal and opposite in direction • Net force causes object to move in direction of force

7. Practice finding net force!

8. Inertia and Mass • Inertia – the tendency of an object to resist changes in its motion • The greater the mass of an object the greater its inertia • Newton’s First Law of Motion – an object moves at a constant velocity until a net force acts on it • An object at rest will remain at rest unless a force acts on it

9. Common Forces • Gravity – the attraction two objects have for one another • Air resistance – resistance an object feels when traveling through air • Friction – resistance to motion caused by two objects in contact with one another.

11. Your Turn!!