1. Mechanics
Topic 2.1 Kinematics

2. Kinematic Concepts Displacement
Is a measured distance in a given direction
It tells us not only the distance of the object from a particular reference point but also the direction from that reference point
It is a vector quantity
In many situations it is measured from the origin of a Cartesian co-ordinate system

3. Kinematic Concepts Speed Is the rate of change of distance
Or the distance covered per unit time
Speed is the total distance (d) covered in total time (t)
Speed (s) = total distance (d) total time (t)

4. Kinematic Concepts Velocity Is the rate of change of displacement
Is a measured speed in a given direction
It tells us not only the speed of the object but also the direction
It is a vector quantity

5. Average Velocity
Defined as the total displacement (s) of the object in the total time (t)
Velocity (vav) = total displacement (s) total time (t)
vav = s t
Where  indicates a small change in the value

6. Instantaneous Velocity
Is the velocity at any one instant
v = s t
Where t is tending towards zero

7. Kinematic Concepts Acceleration
Is the rate of change of velocity in a given direction
a = v / t (where v = v – u)
It is a vector quantity
If the acceleration of an object is positive then we understand its rate of change of velocity to be positive and it could mean that its speed is increasing
Do not think of acceleration as a ´slowing up´or a ´getting faster´.

8. Graphical Representation of Motion
These come in 4 forms
1. Distance-time graphs
2. Displacement-time graphs
3. Velocity-time graphs
4. Acceleration-time graphs

9. Gradiants of Graphs
Gradiant of a Displacement-time graph is the velocity (instantaneous or average?)
Gradiant of a Velocity-time graph is the acceleration (instantaneous or average?)

10. Areas Under Graphs
Area under a Velocity-time graph is the displacement
Area under a Acceleration-time graph is the velocity
Areas can be calculated by the addition of geometric shapes

11. Uniformly Accelerated Motion
Velocity and hence Acceleration can be measured using
Light gates
Strobe photographs
Ticker tape timers