Addition of vectors

What happens when, if travelling forward at 100 km/hr, you throw something backwards at 100 km/hr?
It may be tricky to demonstrate in class, so here are a couple of useful resources.

From a Japanese TV show – a real life example of adding vectors and relative motion. Scroll forward to the 3 min mark if this doesn’t happen automatically.

Then Mythbusters wanted to try it

Can you explain why?

Isn’t Physics just mad Ted?

Now for something completely different (well there are some references to direction in there, so it just about qualifies).

Links to each of these resources are available on the Vectors page of


Some fun teaching Vectors

This week we were looking at Vectors. It can become a bit tedious so no harm to introduce the topic with a fun puzzler.
So you’re travelling in a pick-up at 30 mph and you fire your beer bottle backwards at exactly the same speed. What happens?
Well Naturally Mythbusters had to find out.

The original was Japanese:

And finally, for a few minutes fun at the end of the class, what happens when the second largest ship in the US Navy is on patrol in the Irish Sea and encounters . . .

For teaching addition of Vectors the pHet site is very useful

These links can all be accessed through the Vectors page of the website.