Vectors: Why Cally is always late for school

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Vectors are misunderstood creatures. People think they are complicated.

The letters. The half arrows above them. And what are those waves above the letter?

But they’re really not. Vectors are all about getting from point to point in the right direction.

Just like in this story of Cally.

The journey to school is a long and uncertain one. Even though Google Maps say it takes a 20-minute walk, Cally says it’s never true. And as a result, it’s always late.

GG maps

It’s very puzzling.

So we followed it to school one day.

We started off at a good pace. It was sunny but cool. The walkway was clear as it was only 6 am. School only starts at 6.30 am.

Then, Cally spotted a bakery.

Cally decided to pop by the bakery and get a piece of bread to satisfy its poor tummy.

In the same bakery, Cally caught a whiff of tantalising hot chocolate.

And because Cally is someone with little self-control, it stopped and got a cup.

Now, finally, it’s contented. But when it looks at its watch…

Cally dashes to school, but it’s still late. As usual.

To get from home to school, Cally could have gone from H to S.

But it went from H to B, and from B to S. And that took it much longer than it should.

\vec{HS} = \vec{HB} + \vec{BS}

In