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Forces and Motion

How to Calculate Speed or Velocity.

How is the Velocity of an Object Calculated?

Either Speed or Velocity = Distance ÷ Time.

For example, if an object moving in a straight line
travels 25 metres in 5 seconds,
then its velocity = 25 ÷ 5
                         = 5 m/s.

You must always say what the units are!
(in this case m/s, called "metres per second").
Always check what units are given in the question.
If the time is given in hours or minutes,
then convert it to seconds before doing the calculation.

What is Constant Velocity?

If an objects velocity does not change, we say that it has
a constant velocity. In the above example,
we are not told whether the object has a constant velocity,
or whether its velocity has changed during the 5 seconds.

If the velocity has changed, then the
answer we have calculated is an average velocity of 5 m/s.
If the velocity has not changed,
then the object had a constant velocity of 5 m/s.

When an objects velocity changes, it is called acceleration.

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