1. Motion

2. Physics Science that involves matter and its motion through space and time. We just finished Chemistry: Study of the properties and behavior of matter.

3. Distance and Displacement

4. How fast is this lady running? Earth spins at 1670 km/hr And it is moving around the sun at 107,000 km/hr

5. Distance and Displacement To describe motion accurately, a frame of reference is necessary. Frame of reference is a system of objects who are not moving with respect to one another. – Ex: Earth is the “stationary” frame of reference when cops measure the speed of our cars.

6. Measuring Distance Distance: the length of a path between two points Classroom examples?

7. Measuring Distance The SI unit for measuring distance is the Meter (m). WE WILL NOT BE USING MILES, FEET, or INCHES in Science class!! Why do we use metric?

8. Measuring Distance Large distances are measured in Kilometers (km). One kilometer is equivalent to how many meters? One centimeter is one hundredth of a meter!

9. Measuring Displacement What is distance? Displacement: The DIRECTION from the starting point and the LENGTH of a straight line from the starting point to the ending point.

10. Measuring Displacement Walk 10 blocks Walk 10 blocks north from Kroger

11. Combining Displacements Vector: Quantity that has magnitude and direction. Magnitude can be size, length, or amount. Arrows are used to represent vectors. Size of the arrow corresponds to magnitude (size)

12. Combining Displacements Vector addition is the combining of vector magnitudes and directions. Add displacements using vector addition.

13. Combining Displacements Displacements along a straight line.

14. Combining Displacements

19. Displacement that isn’t Along a Straight Path Resultant Vectors: Vector sum of 2 or more vectors.

20. Speed and Velocity Speed – Average speed – Instantaneous speed Graphing Motion Velocity Combining Velocities

21. Speed Speed: The ratio of the distance an object moves compared to the amount of time the object moves. SI unit for speed is meters/second (m/s). If a car travels 40 km in 5 hours, how fast is the car moving?

22. Speed Average Speed: Computed for the ENTIRE DURATION of the trip. Instantaneous Speed: Measured at a particular instance.

23. Average Speed Average speed (v) = total distance traveled (d) divided by the total time (t).

24. Average Speed

28. Instantaneous Speed Instantaneous Speed: The rate at which an object is moving at a given moment in time. – A car’s speedometer measures instantaneous speed.

29. Graphing Motion A distance-time graph is a good way to describe motion. – What do you think is on a distance-time graph?

30. Graphing Motion The slope of the line on a distance-time graph is the speed of the object in motion!

31. Graphing Motion

33. Velocity Velocity: the speed and direction in which an object is moving. Velocity is a description of both the speed and the direction an object is moving. Velocity is a vector!

34. Velocity A change in velocity can result from a change in direction OR a change in speed. YOU DO NOT HAVE TO SPEED UP OR SLOW DOWN TO CHANGE YOUR VELOCITY!

35. Velocity You can add velocities by vector addition!

36. Velocity Vector addition Resultant Vector

37. Quick Quiz The ratio of the distance an object moves over the amount of time it took for that object to get there represents that objects… a. Acceleration b. Speed c. Distance d. Displacement

38. 2.What does the slope on a distance-time graph represent? a.Displacement b.Distance c.Acceleration d.Speed

39. 3.The description of both speed and direction of motion is known as that object’s a.Speed b.Velocity c.Acceleration d.Displacement

40. 4.A car travels 85km from Columbus to Northridge, then 45km from Northridge to Newark. The total trip took 2 hours. What was the average speed of this car?

41. 5.Carissa walks from Northridge to Johnstown. Johnstown is South of Northridge. She travels for 2 hours at an average speed of 1m/s. How far does Carissa travel in that time? What is Carissa’s velocity?

42. Acceleration

43. What is acceleration? Calculating Acceleration Graphs of accelerated motion

44. Acceleration Acceleration: Changes in speed, changes in direction, or BOTH!

45. Acceleration Any changes in an objects velocity. This includes an increase OR a decrease in speed. Deceleration: Acceleration that slows an object’s speed.

46. Acceleration SI unit: meters per second per second. (m/s²) Gravity= 9.8m/s² Each second an object is in free fall its velocity will increase downward by 9.8m/s.

47. Acceleration ANY change in direction is considered acceleration, even if you are traveling at a constant speed!

48. Acceleration

49. Constant acceleration: steady change in velocity. The velocity of the object changes by the same amount each second the object is in motion.

50. Acceleration MATH!! How would you calculate acceleration?

51. Calculating Acceleration Acceleration can be calculated by dividing the change in velocity by the total time. Acceleration = (VF – VI)/t

52. Calculating Acceleration Acceleration can change even when velocity is constant. – How is this possible?

53. Calculating Acceleration A ball rolls down a ramp, starting from rest. After 2 seconds, its velocity is 6m/s. What is the acceleration of the ball?

54. Graphs of Accelerated Motion What represents acceleration on speed-time graph?

55. Graphs of Accelerated Motion

58. Instantaneous Acceleration Instantaneous acceleration: How fast a velocity is changing at a specific instant. At every moment you have an instantaneous acceleration!