1. http://www.youtube.com/watch?v=xKmhS4qLj_s The Motion Song

2. describe the motion you saw.
2. What is motion?
Motion is an object’s change in position relative or compared to a point of reference.
If your point of reference was the moon . . .
describe the motion you saw.

3. Reference point
A reference point is a place or object used for comparison to determine if something is in motion.
An Object moves if it the position of the object changes in relation to a reference point.
The reference point in usually a stationary object (object not moving ex. Tree or building)

4. 3. Motion Unit Primary Objective:
We will describe and analyze motion in terms of:
Distance
Direction
Displacement
Speed
Velocity
Acceleration

5. 4. Ways we measure motion:
Distance = total length of the path the object took.
Direction = which way. Ex: north, south, up, down, etc.
Displacement = The line from starting point to ending point (as the crow flies)

6. 5. Distance Vs. Displacement
The soccer field is 225 feet by 150 feet.
18 feet
22 feet

7. 6. Distance vs. Displacement
Line A-B is equal to _______________________, while line A-C + C-B is equal to ____________. A C B

8. 7. Which is Which? Distance vs. Displacement
Juan rode his bike around the block to get to Matt’s house.
A bird flew from McDonald’s to Arby’s in a straight line.
In order to get to the Post Office, Wanda had to drive around the Library and Police Station.

9. 8. Speed and Velocity Speed describes how fast an object moves.
50 km/hr
Velocity describes how fast an object moves and the direction of that movement.
50 km/hr EAST

10. 9. Speed vs. Velocity
Speed is a scalar quantity – it is measured only in terms of how much distance has been traveled per unit time.
Velocity is a vector quantity – it is measured in terms of how much distance has been traveled per unit time and in what direction.

11. Speed and Velocity

12. 11. Which is Which? Speed or Velocity?
km/hr
m/s down
m/s
4. 9 m/s to the east

13. 12. Average Speed Average Speed = Distance / Time
Direction doesn’t matter
Ex. 1.) A car travels 50 miles in 2 hours What is its speed?
50/2 = 25 mph
Ex. 2.) A car travels 50 miles east for 2 hours and then 40 miles south for 1 hour What is its average speed?
( ) /(2+1) = 30 mph
Direction is given but doesn’t matter.

14. 13. Average Speed Practice
What was the average speed of the following?
A car that traveled 140 miles in 2 hours?
A motorcycle that traveled 60 km in 1.5 hours?
3. A canoe that traveled 5 km in 2 hours?

15. Average Speed: show your work and include the units!
1. Andre ran 3 miles in 21 minutes. What was his speed in miles/minute? 2. Andre got tired and started to walk. He walked 3 more miles but it took him 39 minutes. What was his speed in miles/minute? 3. What was his average speed for the 6 mile trip?