Speed and Velocity

In I/GCSE Physics, in order to properly understand the formula for **Speed** or **Velocity** we must understand the logic behind it. The formula for Speed is ‘**s/t**’ when **s = distance** and **t = time**.

To explain this equation we must think about it with regards to distribution. **‘s/t’ is the same as ‘s ÷ t’**, so what we’re doing here is equally distributing the amount of distance we have covered onto the amount of time we have taken to cover it when in terms of seconds; five metres **per second** in this case.

- In the I/GCSE physics,
**speed**is defined as the specified amount of distance travelled**over a specified amount of time**. e.g. The car was moving at 25m/s (m = Metres, s = Seconds). Speed is a**Scalar**.*s/t = speed*. **Velocity**is defined as**Speed plus a specified direction**. e.g. The car was moving North at 25m/s. Velocity is a**Vector**.*s/t + specified direction*(right, left, north, south, etc.) = Velocity.

Example:

You are driving for 5 seconds and travel a distance of 25 metres.

Diagram:

In I/GCSE physics curriculum, by explanation, we are evenly dividing the amount of distance we have covered among each second (25÷5=5). So, **s/t = s÷t** which is simply shorthand for the diagram above; for each second we have travelled **five metres**.

- Formula for Speed:
**s/t (Distance ÷ Time)**. - [Scalar: A Scalar the term used for a ‘scalable’ value. It is only a value and cannot have anything else specified e.g. a direction.]
- Formula for Velocity:
**s/t + Specified Direction**. e.g. right, left, north, south, etc. - [Vector: A Vector is a Scalar with a specified direction.]

Challenge:

a) A car travels 500 metres in 20 minutes, how fast was the car going?

End of this topic!