1. “Distance - Time Graphs” Pages 320-326

2. What are the characteristics of a d-t graph?
A Distance-Time graph plots the distance traveled by an object on the y axis and the time on the x- axis
The speed is the slope (steepness) of the line. The more steep a line is the faster the object is moving.
Speed is scalar ( only has magnitude no direction)
Increase distance is represented by a rising line. A flat line means the object is not moving.

3. What are the characteristics of a d-t graph?
Distance-Time Graph
Distance
Speed
Change over time
Y-axis = Distance
How far away the object is from the reference point (0,0)
Units: cm, m, km,,
X-axis = Time
Units: s, m, hrs
Distn

4. What are the characteristics of a d-t graph?
Each graph starts at a reference (starting) point at (0,0).
As time progresses, the object may move away or towards the reference point.

5. What are the characteristics of a d-t graph?
Slope: the average speed of an object
change in y (rise)
Slope =
change in x (run)
Slope units = m/s.
(y2-y1)/(x2-x1) Ex
= 14 m/s
10-5

6. What does the slope of the line mean?
Examine the slope of the line in order to interpret the speed at which it is moving.
A linear slope (straight line) means that they are moving at a constant speed.
Steeper lines mean the object is moving faster.
Less steep lines mean the object is moving slower.
Horizontal lines mean the object is not moving.

7. What is taking place between 4-6 hours?
Is she moving at a faster rate from
6-8 hrs OR 8-10 hrs?

8. Review D-T Graph Concepts
What does the y-axis display?
What does the x axis display?
What is the slope
How do we calculate the slope?
What is the reference point?

9. Acceleration The rate at which velocity changes
Velocity is a vector: it has speed and direction.
Two objects can have the same speed but different velocities because they are going in opposite directions
Has magnitude (length of acceleration ex. 10m/s/s
Has direction (direction of acceleration North)
Acceleration = 10m/s2 N

10. Acceleration occurs when velocity changes
It is the rate of change in velocity
The difference in velocity between when the object starts moving and when it ends its movement.
It is Velocity ÷ Time
It is measured in meters per second per second or meters per second squared (m/s2) or

11. Producing acceleration requires force
In order to produce an acceleration, a force must be applied to an object.
The type of acceleration depends on
Magnitude of Force
Direction of Force
Direction of motion of the object
Ex. A force acting in the same direction will change the speed not direction.

12. Everyday Versus Physical Science Usage
Everyday life
Acceleration means an increase in speed
Deceleration means a decrease in speed
In Physics
Acceleration refers to any change in speed (increase and decrease)
It is a vector
It can change speed, direction, or both.
It can be positive (increase velocity) or negative (decrease velocity)

14. How is average acceleration calculated?

15. Centripetal acceleration
Acceleration that results in circular motion
Always Changing in direction but not always speed
It is always experience acceleration because it is always changing direction
Term coined by Sir Isaac Newton when he discovered centripetal force
Comes from the Latin word centrum which means center and petere which means to rush