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TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Physics > Motion - velocity and acceleration and related equations

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Scalar

A quantity with only magnitude and units. e.g. Mass, Speed, Energy. Speed and distance are both scalars.

Vector

• A quantity with magnitude, direction and units.
• Velocity and displacement are vectors because they have magnitude and direction.
• Velocity = Displacement / Time.
• It is also the gradient of a displacement/time graph.
• Units: ms^-1

Displacement

• How far an object has moved from a certain position.
• Positive and negative displacement show movement in opposite directions. Units: m

Acceleration

• Rate of change of velocity.
• It is also the gradient of a velocity-time graph.
• A positive acceleration shows speeding up and vice versa.
• Change in velocity / time
• Units ms^-2

The equations

= displacement

= initial velocity

= final velocity

= acceleration

= time

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