Chapter 1, Section 1

1
Chapter 1, Section 1

• Speed and Motion

2
Recognizing Motion

1. Whats happening to the distance between the bus
   and the light posts as the bus is moving?
2. Which of the two objects is a reference point? So
   what is a reference point?
3. What reference points do you see when you walk to
   school or class?

3
Calculating Speed

• What is the average speed limit on the freeway?
• What are the two parts of a speed measurement?
• Speed

4
Calculating Speed

• Speed
• What is the dogs speed?
• 30m/15s 2m/s

time 0 s distance 0 m
t 15 s d 30 m
5
Making a Speed Graph
X (Time in sec) Y (Distance in meters)
0 0
1 5
2 20
3 45
4 80
5 125
6
Speed
7
Slope RISE/RUNONLY for straight parts of a
graph!
RISE
RUN
8
Constant Speed

• If a ship traveling in the ocean keeps the same
  speed for several hours, it is going at a
  _________ speed.
• A horse ran 21 meters in 3 seconds, what was its
  speed?
• 21 m 3 s 7m/s

9
Average Speed

• When a bicyclist is racing up and down mountains,
  his speed _______.
• You can use the ________ speed to describe the
  motion of that bicyclist at every point during
  the race.

10
Average Speed

• Average Speed
• total distance total time
• If a cyclist travels 32 km in the first 2 hours
  and 13 km in the last 1 hour, what was his
  average speed?
• 32km 13km 45km
• 2h 1h 3h
• 45km 3h 15km/h

11
Velocity

• Velocity always includes speed and ___________.
• Which is an example of velocity?
• Wind at 30mi/hr heading east
• Car traveling 65mi/hr

12
Exploring Motion Graphs

1. Is this graph showing a constant speed?
2. What is the total time distance?

13
Exploring Motion Graphs

1. What happened during the 6th to 8th minutes?

1. What effect did that have on the average speed?

14
Exploring Motion Graphs

1. What is the difference between the joggers
   speed on the third day and the first day?

1. What is the total distance time?

15
Solving Speed Problems

• Use the Speed Triangle
• Figure out if you must find speed, time or
  distance from the problem.
• Cover up the letter you are trying to find to see
  what you must do.

16
Speed, Time, Distance Practice Problems

1. Which has a greater speed, a hawk that travels
   600m in 60s, or an eagle flying 60m in 5s?
2. How long would it take to travel 30 meters if you
   were running at a speed of 2 meters/second?
3. If your average speed in a car was 45 miles/hour,
   how far would you get if you drove for 4 hours?

17
Draw 3 Motion Graphs

1. Label the x and y-axis with time and distance.
2. The first graph should represent slow motion.
3. The second graph should represent a faster
   motion.
4. The third graph should represent an even faster
   motion.

18
Balloon Demonstration

1. Blow up the balloon and hold firmly shut.
2. Describe the motion of the balloon right now.
3. What could you do to make the balloon move?
4. Release the balloon and describe when the balloon
   changes its speed or direction.