1. Physical Science Review Physics

2. Get out Paper Write the notes you think are necessary Working on chps 1,10,11,12 Will be continued Thursday and Friday

3. Scientific notation 3 x 10 4 m = 3 x 10,000 = 30,000 m 3 x 10 -4 m = 3 / 10,000 = 0.0003 m

4. Basic measurements Length – meters Mass- the amount of matter in an object, measured in kg Time – seconds These are SI-units (international standards)

5. Metric prefixes 1 kilogram = 1000 grams 100 centimeters = 1 meter 1 second = 1000 milliseconds

6. Metric conversions 245 cm = ________ m 34.5 kg = __________ g

7. Scientific notation 3 x 10 3 m = 3000 m 3 x 10 -3 m = 0.003 m

8. Weight The force of gravity applied to object Equals mass x acceleration due to gravity (g) g = 9.8 m/s 2 on Earth

9. Kinematics The study of how things move

10. Measuring length Displacement – difference between start and finish position (Magnitude and Direction) Distance – Length of path (magnitude, no direction)

11. Measuring how fast Velocity – rate of motion –Displacement / time (direction counts) Speed – rate of motion –Distance/ time (no direction) Both have units of m/s

12. Calculate constant velocity v = d / t

13. *Relative motion Speed based on comparison to objects or features in environment Ex: Person walking down aisle of a moving bus

14. Acceleration Rate of change in velocity m/s 2 equals Velocity / time Accelerating when speeding up, slowing down or changing direction

15. The calculate acceleration a = (v f – v i ) / t What is acceleration of a car that starts from rest and reaches 5.3 m/s in 13 seconds?

16. Questions What is the difference between distance and displacement? What is the difference between an object accelerating versus moving at a constant velocity?

17. Uniform circular motion An object moving at a constant speed around a circular path. Object undergoes acceleration due to change of direction

18. Position-Time graphs Walking in the courtyard Also called distance-time graphs Relate shape of graph to type of motion –Stopped, forward, backward –Constant velocity, speed up, slow down –Acceleration vs. constant velocity

19. P- T graphs, part 2 Horizontal line Sloped line Vertical line Curved line

20. Describe the P-T graph

21. V-T graphs will be on test for on honors Numbers represent how fast an object is going, not its location What motion do these represent? Horizontal line Sloped line Vertical line Curved line

22. Velocity-time graphs May also be called speed-time graphs How is backward motion indicated?

23. Forces Any push or pull on an object Units are Newtons = kg m/s 2

24. Frictional force Related to- Roughness of surfaces and the force pushing surfaces Force is opposite to direction of motion Can not make object move

25. Air resistance force of the air that pushes against a moving object force direction is always opposite motion direction

26. Unbalanced vs balanced forces Unbalanced force: forces in one direction is more than those in the opposite direction Balanced force: –Forces are equal but in opposite direction –equilibrium

27. Inertia The resistance of an object to change in motion Based on mass The object with the greater inertia requires more force to alter its rate of motion Which object on your desk top has the most inertia?

28. Newton’s First Law An object at rest will stay at rest, an object in motion will stay at the same motion, unless acted upon by a net outside force

29. Newton’s Second Law F net = ma

30. Newton’s Third law For every action, there is an equal and opposite reaction

31. Situation A track star pushes off a block with their foot to begin the 100 meter dash. Find a connection between all 3 laws and the situation described above

32. Net force The sum of all forces on an object

33. Normal force Equal to the reactive force of the ground pushing back on object Provide a example from the room of a normal force

34. Free fall An object accelerating only due to gravity

35. Terminal velocity When the gravitational force is balanced by the force of air resistance An object at terminal velocity, the object stops accelerating downward

36. *Free body diagrams A drawing showing how forces are applied to an object Object is represented by a dot Forces are represented by arrows pointing away from dot

37. Draw a free-body diagram Of an sky diver at terminal velocity Of a baseball getting hit by a bat on a windy day

38. Momentum Equals an objects mass times its velocity P=mv Inertia in motion, pain index of impacts Which has more momentum, a parked car, a runner, an airplane moving at 100 m/s

39. Change of momentum Momentum only changes if a net force is applied to object Velocity is the easiest value to change

40. Auto accidents Is the change of momentum of the driver the same, greater or less if an air bag is used to stop the forward motion of the driver?

41. Automobile Accidents and change in momentum Safety features include, air bags, padded steering wheel and dashboard, crumple zones, seat belts All safety features –can NOT alter the size of the change in momentum –but EXTENDS the time the change takes place, lowering force applied

42. Conservation of momentum Momentum can be transferred to another object upon impact Momentum is not created or destroyed Mr. Baker shooting a gun, what is the sum of the momentum of both the gun and bullet before and after the shooting?

43. Work Ability of a force to move an object W = F x d Joules Force and motion must be in same direction

44. Power The rate of doing work P = W/t Watts

45. Mechanical advantage The ratio of the amount of force got from machine to force put into machine MA = f o / f i

46. Simple machines advantages 1) Mechanical (force) advantage (more force out of machine than put in) 2) direction change 3) more distance out is than distance in using machine

47. Simple machines Pulley – used to raise a curtain Inclined plane – ramp Wedge – knife edge Screw – spiral stair case Wheel and axle – doorknob

48. Levers 1 st class (fulcrum in middle)- seesaw 2 nd class (outgoing force in middle)- wheelbarrow 3 rd class (incoming force in middle) Broom

49. Compound machine Machine made out of 2 or more simple machines scissors

50. Energy The ability to do work The amount of work done = energy expended Joules

51. Energy types Potential – stored energy –GPE – energy of position –EPE – energy of deformation Kinetic energy – energy involved with motion Mechanical energy = sum of potential and kinetic energy

52. Law of conservation of energy Energy can not be created or destroyed, only transferred /transformed

53. Roller coasters Where would the car have the most GPE? Where would the car have the most KE? TE?