P2 Chapter 1 Revision

1.1 Distance - time Graphs

Speed formula triangle (http://dspace.jorum.ac.uk/xmlui/bitstream/handle/10949/1004/Items/T175_8_025i.jpg)

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Velocity is speed in a given direction.
Velocity is sometimes a more useful measure of motion, because it describes both speed and direction.
The acceleration of an object is its change of velocity per second.
Acceleration is measured in metres pre second squared.
Acceleration = change in velocity (m/s)/ time taken for change (s)
A body travelling at a steady speed is accelerating if its direction is changing.
We use the term negative deceleration in any situation where an object slows down.

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The slope of the line on a velocity-time graoh represents acceleration.
Braking reduces the velocity of a vehicle.
The area under any section of the graph is equal to the displacement (distance) travelled in that time interval.
The area under the line on a velocity-time graph represents distance travelled.

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For an object moving at a constant speed, the distance-time graph is a straight line.
For a moving object with a changing speed, the distance-time graph is not a straight line.
The slope on a velocity-time graph represents acceleration.
To find the distance travelled from the graph, remember the area under a velocity-time graph represents the distance travelled.

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