1. Matter in Motion
Chapter 1
Page 3

2. Measuring motion
Section 1

3. Measuring Motion
An objects change in position over time when compared with a reference point

4. Motion is relative
If you are in a car that is going at the same speed, the other car will not by moving with respect to you. But both cars are moving with respect to the ground.

5. Reference point Any object that will appear to stay in place
Moving objects can be used as reference points

6. Point of Reference cont
In talking about motion, it is important to indicate your point of reference. In the case of moving automobiles, it is usually assumed the speed is with respect to the ground. But there are situations where the speed or velocity may be with respect to another object or an observer.

7. Example
For example, suppose a car was traveling at 60 miles per hour (mph) and hit another car, but there was hardly a dent. The reason is that the second car was traveling in the same direction at 59 mph, so the car was going only 1 mph with respect to the second car when it hit it.

8. Sun looks like it is moving in the sky
The sun appears to move across the sky, when the earth is actually spinning and causing that apparent motion.
Usually, we consider motion with respect to the ground or the Earth. Within the Universe there is no real fixed point.
The basis for Einstein's Theory of Relativity is that all motion is relative to what you define as a fixed point.

9. Speed Depends on distance and time
Speed the rate at which an object moves
SI unit is meters/seconds (m/s)

10. Average Speed
Objects do not travel at constant speed therefore we calculate average speed
Average Speed = Total Distance
Total time

11. Calculating Average Speed

12. Answers

13. Practice

14. Find the average

15. Practice

16. Steps

17. Practice

18. Answers

19. Velocity
The speed of objects in a particular direction

20. Velocity
The final component in explaining an object's velocity is including a relative direction. For example, a car that travels 100 meters in 10 seconds, in the westerly direction, would have a velocity of 10 m/s west.

21. Acceleration: The rate at which velocity changes
measured by taking the change in velocity of an object divided by the time is took to change that velocity:

22. Acceleration
For example, if an object speeds up from a velocity of 240 meters/second to 560 meters/second in a time period of 10 seconds, the acceleration is ( )/10 = 320/10 = 32 m/s/s or 32 m/s².

23. Practice Problems Math Break
Page 5
Page 9

24. Graphing

25. The Speed a Car travels

26. Section 2 Terms to learn: force, net force, newton
What is Force
Section 2
Terms to learn: force, net force, newton

27. Force
Push or pull

29. Determining the Net Force
Net force: The sum of all the forces which act upon an object

30. Vectors

31. Unbalanced = Motion

32. Balanced = No Motion

35. Friction
Section 3

36. Friction
Any force that opposes motion b/t two surfaces that are touching

37. Sliding Friction Very effective a opposing force
Lot of force must be exert to overcome

38. Rolling Friction
A rolling wheel requires a certain amount of friction so that the point of contact of the wheel with the surface will not slip.

39. Fluid Friction Friction forces formed b/t liquids and another surface
Streamlining reduces fluid friction

40. Friction = Force Applied= No Motion
Static Friction
The force of friction that is equal to force applied
Friction = Force Applied= No Motion

41. Ways to change Friction
Reduce
Lubrication
Streamlining
Increase
Add texture
Add force

42. Gravity: A force of Attraction
Section 4

43. Gravity
A force of attraction b/t object due to its mass

44. Newton’s Idea Unbalanced forces caused an apple to fall from a tree
He realized the two forces are one gravity

45. Law of Universal Gravitation
All objects in in the universe attract each other through gravitational force

46. Forces in action Mass Weight How much matter it contains.
It is measured in grams (g) or kilograms (kg) but is NOT a force.
Weight
The force caused by gravity pulling down on the mass of an object.
It is measured in Newtons (N).

47. Size of Force Depends Mass Distance
Larger the mass the greater the force of gravity
Distance
Closer the distance the greater the force of gravity