1. Section 1: Describing and measuring Motion
Chapter 1: Motion
Section 1: Describing and measuring Motion

2. Observing Motion
Motion- distance from another object is changing.
Reference Point- object that is used for comparison to determine if something is in motion.

3. Draw a hot air balloon in motion and show how it has moved relative to a reference point.

4. Calculating Speed:
Speed- the distance traveled by an object divided by the time taken to travel that distance.

5. Formula for Speed

6. The SI unit for speed include:
meters per second (m/s)
kilometers per second (km/s)
feet per second (ft/s)
miles per hour (mi/h)
yards per second (y/s)

7. Average Speed
Most of the time, objects do not move at a constant speed.
Formula:
Average speed = total distance
total time

8. Instantaneous Speed: the rate at which an object is moving at a given instant in time.
Example: Car speedometer

9. Let’s do some practice problems!
Formula practice
Average speed lab

10. Speed on a Graph Speed can be represented on a distance-time graph.
x-axis = time
y-axis = distance
The slope of the line on a distance-time graph for speed represents the rate of speed.

12. Usain Bolt

13. Calculate Usain Bolt’s Average Speed
Distance: 100 meter
Time: 9.58 seconds
Average Speed = 100m
9.58s
Bolt’s Average Speed = m/s

15. Let’s do some practice - Motion in a line practice sheets

16. Velocity Example- an airplane traveling 600 km/h south.
Velocity- is the speed of an object in a given direction.
Speed and direction need to be constant
Example- an airplane traveling 600 km/h south.
Constant velocity is always motion along a straight line.

17. Chapter 1: Section 3 Acceleration
Note: We skipped chapter 1: Section 2!

18. Acceleration
Acceleration- the rate at which velocity changes over time.
Remember: velocity involves both speed and direction.
An object accelerates if it;
1) changes direction or,
2) changes speed

20. Types of Acceleration
Acceleration is commonly associated with an increase in speed, but an object accelerates if it changes direction as well. Even if a car is moving at a constant speed its velocity changes when it makes a turn.
positive acceleration- an increase in velocity
(This is the same as speeding up in the positive direction or slowing down in the negative direction.)
negative acceleration- a decrease in velocity
(This is the same as slowing down in the positive direction or speeding up in the negative direction.)

21. Calculating Acceleration
Acceleration = final velocity – initial velocity time Final = ending velocity Initial = starting velocity

22. Some common units for acceleration are: - meters per second per second (m/s/s or m/s2) - kilometers per hour per second (km/h/s)

23. As a roller coaster car starts down a slope, its speed is 4m/s
As a roller coaster car starts down a slope, its speed is 4m/s. But 3 seconds later, at the bottom its speed is 22m/s. What is its average acceleration?
Initial Speed: 4m/s
Final Speed: 22m/s
Time: 3s

24. Formula: A = final velocity – initial velocity time Substitution: 22m/s – 4m/s 3s Answer: 6m/s2

25. Let’s practice some acceleration problems

26. Graphing Acceleration
Acceleration can be represented on a velocity- time or speed-time graph.
x-axis = time
y-axis = velocity or speed

27. Velocity-Time Graph

28. Velocity-Time Graph

29. Let’s look at some graphs