2. L2 Forces, Mass, Acceleration, Pressure, Review of Exponents

3. Frictionless motion Demo

4. 5.NEWTON’S FIRST LAW OF MOTION Newton finished the overthrow of Aristotelian ideas. Law 1 (Law of Inertia) Every object continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. “If you leave an object alone, it has constant velocity.”

5. Newton's concept of motion said that the natural state of an object was (a) constant velocity (b) constant acceleration (c) constant net force

6. Inertial mass

7. We call the change in velocity per unit time the acceleration a= Δv/ Δt The Δv can be in magnitude and/or direction

8. 1.FORCE CAUSES ACCELERATION The combination of forces that act on an object is the net force. (Only the net force is shown in the figures on this slide.) Fa Fa Fa The acceleration of an object is directly proportional to the net force. mmm This symbol means proportional to

9.  The force in each of these equations represents the vector sum of all of the forces acting on the object of mass m.  Units of force - N and lb or 5. NEWTON’S SECOND LAW OF MOTION

10. slug)  A slug weighs  Every object possesses inertia (mass).  Inertia is the sluggishness of an object to changes in its state of motion.  Mass - a measure of the inertia of an object (Units - kg and 3.MASS AND WEIGHT 32 lb.  Inertia deals with how hard it is to start and stop an object.

11. Gravitational Mass

12. Newton's Law of Universal Gravitation r m1m1 m2m2

13. 2.The Universal Gravitational Constant, G

14. At earth’s surface, F = G mM e /R e 2 or W = (Gm e/ Re 2 ) m or W=(g)m or weight = mass x acceleration of gravity g = 9.8 m/s 2

15. A 2 kg mass weighs: A) 2 N B) 19.6 N C) 32 N D) 10 5 N E) Not enough information given

16. 2 Concepts of Mass: Equivalence of gravitational mass and Inertial mass Theory of General relativity

17. Pressure=Force/contact area On left, the pressure on the bottom block, i.e. the weight of the top block/contact area, is lower than the pressure on the bottom block on the right.

19. Pressure in a fluid (including air!)

22. Exponential Notation

23. 1000 = 10 x 10 x 10 = 10 3 100 = 10 x 10 = 10 2 10 = 10 1 1 = 10 0 0.1 = 1/10 = 10 -1 0.01 = 1/100 = 10 -2 0.001 = 1/1000 = 10 -3

24. Ordinary decimal notationScientific notation (normalised) 3003×10 2 4,0004×10 3 5,720,000,0005.72×10 9 −0.0000000061−6.1×10 −9

25. For CAPA, we write 356 as 3.56E2

26. 10 -2 x 10 +6 = 10 4 10 -2 /10 6 = 10 -8