1. To introduce Kinematics
Definitions
Displacement – time graphs
Velocity – time graphs

2. Work for 20 / 9 / 16
Read the slides and copy out all the definitions for displacement, speed, instantaneous speed, average speed, acceleration and the displacement – time and velocity – time graphs.
Complete the questions about the different graphs both in the presentation and from the worksheet ‘Graphs’.

3. Definitions
Displacement is the distance moved by a body in a specified direction
It is a vector quantity

4. Definitions continued
Speed is the rate of change of distance
It is a scalar quantity
Units are ms-1
Instantaneous speed is the speed at any given instant
On a car journey instantaneous speed is continually changing and it is shown on the speedometer reading
Average speed = distance travelled
time taken

5. Definitions continued
Velocity is the rate of change of displacement of a body
It is a vector quantity, so its value may be positive or negative depending on the direction of motion
Units are ms-1
Velocity = change in displacement
time taken

6. Definitions continued
Acceleration is the rate of change of velocity of a body
It is a vector quantity so its value may be positive or negative
Acceleration = Change in velocity
Time taken

7. Displacement time graphs
Displacement (s) is plotted vertically against time (t) horizontally
Gradient of a (s,t) graph = Velocity s s s s t t t t
Copy out the sketch graphs and describe the motion in terms of velocity. Remember to include whether it is +ve or –ve
What would be happening if the line was curved?

8. Velocity time graphs
Velocity(v) is plotted vertically against time (t) horizontally
Gradient of a (v,t) graph = acceleration
Area under a (v,t) graph = distance travelled v v v v t t t t
Copy out the sketch graphs and describe the motion in terms of acceleration. Remember to include whether it is +ve or –ve
Describe the motion if the line was curved.

9. Copy out and draw the corresponding graphs?