2. Isaac Newton

3. Newton’s First Law "Every body perseveres in its state of being at rest or of moving uniformly straight forward except insofar as it is compelled to change its state by forces impressed." (Principia) An object in motion will remain in motion and an object at rest will remain at rest unless acted on by an outside force. Inertia

4. Newton’s First Demo

5. Newton’s Second Law "A change in motion is proportional to the motive force impressed and takes place along the straight line in which that force is impressed.” (Principia) First Part: When I push something, the distance it moves depends on how hard I push it. Second Part: If I push something, it moves in the direction that I pushed it.

6. The Most Useful Equation Newton’s Second Law: (Force = derivative of momentum)

7. Newton’s Second Law Derived

8. Special Case: Gravity

9. Newton’s Third Law "If one object exerts a force on another the other exerts the same force on the one" (Principia) “For every action there is an equal and opposite reaction!” ACTION = -REACTION

10. Newton’s Third Law: Falling F Earth on Bubar = F EB F Bubar on Earth = F BE

11. Newton’s Third Law: Falling F EB F BE F EB =F gravity F EB =m Bubar *a F EB =m Bubar *g F EB =70 kg*10 m/s 2 F EB =700 Newtons F EB = -F BE F BE =F EB =700 N F BE =m E *a E a E =F BE /m E a E =700 N/6E24 kg a E ~1E-22 m/s 2 a Bubar = 10 m/s 2 : a Earth =0.0000000000000000000001 m/s 2 Earth on Bubar Bubar on Earth

12. Hero Engine Fwa Fac

13. RECALL Newton’s First Law: Inertia Newton’s Second Law: F=ma Newton’s Third Law: Action=-Reaction

14. Wolf 330

16. Questions? Lesson, demonstrations and additional resources located online at: http://bubarnewtonslaws.wikispaces.com/ Your welcome to try demos after class !