KINEMATICS

1. KINEMATICS

2. KINEMATICS the science of describing the motion of objects (using words, diagrams, numbers, graphs, and equations)

3. MOTION  Motion Is Just A Change In Position. To describe  how an object moves you  need: A ruler to measure where an object is. And a clock to measure when an object is.

4. Describing Motion Scalars- quantities which are fully described by a ONLY a magnitude (size/quantity) Vectors - quantities which are fully described by BOTH a magnitude and a direction

5. Are we there yet? Well… It Depends

6. It depends on if we are talking distance or displacement!

7. A SCALAR quantity which refers to "how much ground an object has covered" during its motion DISTANCE DISPLACEMENT A VECTOR which refers to "how far out of place an object is"; it is the object's change in position

8. The ape runs west 4m, north 2m, east 4m, and south 2m. Distance?Displacement? 0 m 12 m

9. The skier moves from A to B to C to D Distance? Displacement? 420 m 140 m to the right

10. SPEED vs. VELOCITY SPEED A SCALAR quantity which refers to “how fast an object is moving” VELOCITY A VECTOR which refers to “the rate at which an object changes its position”

11. d Velocity V = t speed of an object in a certain direction. V = velocity (meters/second) d = distance (meters) t = time (seconds)

12. Velocity speed of an object in a certain direction. 0 seconds 3 1 2

13. Speed=? Velocity=? B Total time= 4 seconds 20 meters 12 meters 16 meters A

14. Acceleration

15. Acceleration is how quickly velocity changesover time. 0 Speed 3 1 2 Meters/second

16. Acceleration how quickly velocity changes over time. (Vfinal - Vinitial) ___________ A = time

17. The graph below relates speed and time of four cars (1, 2, 3, and 4) traveling along a straight highway. Which two cars move with zero acceleration? 1 and 4 2 and 3 1 and 2 3 and 4

18. Which of the following is certain to change as a ball accelerates? mass of the ball inertia of the ball velocity of the ball force acting on the ball

19. What must happen to an object in order to accelerate it? A net force must be applied. Some weight must be removed. Its frictional coefficient must be reduced. It must contain momentum.

20. Which of these describes the object with the largest acceleration ? An object with a small change in velocity over a small change in time An object with a small change in velocity over a large change in time An object with a large change in velocity over a small change in time An object with a large change in velocity over a large change in time

21. Forces of Nature Gravitational Magnetic

22. Lower mass objects are easier to move . . .and to stop moving.

23. momentum • the force of a moving body. ___________ the mass times velocity of an object p = m • v Momentum = mass xvelocity (Kgrams) (meters/second)

24. Momentum = mass xvelocity momentum Higher mass higher momentum Higher velocity higher momentum p = m • v

25. momentum includes velocity. So, it has direction. Momentum points in the direction of motion.

26. Conservation of momentum When objects collide, all of the momentum goes somewhere.

27. Conservation of momentum When objects collide, all of the momentum goes somewhere.

28. Conservation of momentum When objects collide, all of the momentum goes somewhere.

29. Conservation of momentum When objects collide, all of the momentum goes somewhere.

30. 50 N 100 N 50 N 50 N 100 N 50 N

31. NEWTON’s 3rd Law of Motion: Conservation of energy For every action there is an equal and opposite reaction.

32. NEWTON’s 3rd Law of Motion: For every action, there is an equal and opposite reaction.

33. NEWTON’s 3rd Law of Motion: For every action, there is an equal and opposite reaction.

35. Gravity Inertia Friction Balanced or unbalanced? Action Reaction

36. Gravity balanced UN BALL Speed (m/s) Ground Time (mSec)

37. Inertia PUTTER balanced UN Speed (m/s) BALL Time (mSec)

38. Friction SKATE balanced UN Speed (m/s) Time (Sec)

39. A car is traveling down a hill. Which of the following will affect the amount of energy the car has? how long the car is the time of day how much the car weighs the color of the car

40. Friction • the resistive force that occurs when two surfaces travel past each other. • causes physical deformation • generates heat

41. Friction • the resistive force that occurs when two surfaces contact each other.  

42. Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to get him out the door by sitting on the vinyl floor. sitting on the tile floor. sitting on the carpeted floor. sitting on the wood floor.

43. Pauline needs to measure the sliding friction of a brick. How should she go about doing this? attach the brick to a string and then to a spring scale and read the force needed to quickly lift the brick off the ground drag the brick by a string attached to a spring scale so that it gradually speeds up drag the brick by a string attached to a spring scale along the surface of a table at a constant speed and read the force hang the brick from a string attached to a spring scale and read the force

44. Sliding friction-the drag force created when the surface of one object slides across the surface of another object. Sliding Friction Lab Object Surface force (Newstons)

45. terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster. gravity air resistance

46. In the absence of air resistance, which of these objects will fall at the fastest rate when dropped? the ball with a mass of 75 kg the ball with a mass of 25 kg the ball with a mass of 10 kg They all fall at the same rate.

47. Pressure is the amount of force exerted over a certain area. Pressure = Force Area

48. Pressure = Force (newtons) Area (m2) 1 Pascal = 1 Newton/meter2

49. Work

50. { Distance Work W = f • d Force { Distance