Speed is measured in meters per second


First of all, thank you for creating Exercism. I’m having super fun learning go with it :slight_smile: .

Now to the topic of interest.

I’ve started working through the “need for speed” problem in Go, and while reading I understand that we’re supposed to treat speed as if it has units of length (meters). Well…this doesn’t make much sense to me, so after mentioning it in the IRC channel, I was encouraged to report it here.

To be honest, changing the units of speed to the right ones (m/s) it will complicate a bit more the problem, so it would require some rethinking and redesign.

As it is though, it doesn’t make much sense to me, so I was hoping to trigger a discussion here on why it was chosen to have units of length (as the distance), and also how the problem could look like if speed gets its proper units back (meters per second).

Thanks !

Note the same language is found in C# and Java as well.

1 Like

I think the intent behind the exercise is that the speed is actually in m/s but a simplification has defined s = 1, and then the speed is automatically m. Since theoretically the battery drainage also needs to be per time unit. But since the whole exercise is the time taken for granted that is 1 can you theoretically simplify. This could perhaps be more clearly explained in the exercise but it could just add jitter for some. And I think reworking the exercise to incorporate it into use per time unit is a rather big change.


The language could be refined to be explicit/technically correct without modifying what is being asked of students.

That’s a fair explanation, thanks. Perhaps there could be an addendum at the end or in a box, or somewhere for those that might want to know the details.

1 Like

Could the distance unit be removed completely without any confusion at all?

The scale of the model is not specified, the amp hours are not given for the batteries, the only thing that is stable is the time unit. Everything else being equal, any unit of distance could be used, as I do not believe the tests verify the unit of rate, only the rate ratio.

1 Like