1. Chapter 2 Motion in one Dimension
Mrs. Schwartz
2016

2. Objectives
Describe motion in terms of frame of reference, displacement, time, and velocity.
Calculate the displacement of an object traveling at a known velocity for a specific time interval.
Construct and interpret graphs of position versus time.

3. One Dimensional Motion
To measure motion, you must choose a frame of reference. A frame of reference is a system for specifying the precise location of objects in space and time.

4. Displacement Displacement is a change in position.
Displacement is not always equal to the distance traveled.
The SI unit of displacement is the meter, m.

6. displacement = final position – initial position
x = xf – xi
displacement = final position – initial position Δx

7. Average Velocity
Average velocity is the total displacement divided by the time interval during which the displacement occurred.

8. Sample problem
During a race on level ground, Andrea runs an average velocity of 6.02 m/s to the east. What is Andrea’s displacement after 137s ?
List givens.
List unknown
List equation
Plug in
Solve

9. Heather and matt walk with an average velocity of 0. 98m/s eastward
Heather and matt walk with an average velocity of 0.98m/s eastward. If it takes them34 min to walk to the store, what was their displacement?
If Joe rides his bike in a straight line for 15 min with an average velocity of km/h south, how far has he ridden?
It takes you 9. min to walk with an average velocity of 1.2 m/s to the north from the bus stop to the museum entrance. What is your displacement.
Simpson drives his car with an average velocity of 48.0 km/h to the east. How long will it take him to drive 144km on a straight highway?

10. Velocity and speed
Velocity describes motion with both a direction and a numerical value (a magnitude).
Speed has no direction, only magnitude.
Average speed is equal to the total distance traveled divided by the time interval

11. Speed
Average speed = Distance traveled Time of travel

12. Velocity and graphs
Can also be determined by the slope of a position-time graph
Slope = rise/run

15. Instantaneous vs average
Velocity at some instant. Not the same as average!