Distance vs Displacement: Scalar vs Vector

When you tutor physics, a concept that soon comes up is scalar vs vector.  It’s not something most people ever think much about, but the difference is very important – especially in Science 10 and Physics 11.

For example:  distance is a scalar, but displacement is a vector.  If you drive to the store (10 km away), then return home, of course you’ve driven a distance of 20 km.  Distance is a scalar, so you just add the km going to the ones returning.

For the same situation, your displacement when you get back is 0 km.  That’s because, being a vector, displacement considers the direction as well as the value.  From the displacement point of view, every km you travelled to the store got cancelled out as you returned.  For any round trip, your displacement is 0 km.

Displacement can also be defined as how far you are from where you started.  It includes the direction you are from your start point.  Naturally, if you’re back where you started, your displacement is 0.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Have a great night.

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