A question about metres, seconds, grams and newtons.

[slacktracer]

I'm very interested in using matter.js for a project (the demos are very compelling) but I must know something first, hope you're able to help me, when I set an body size or apply a force is it like I'm defining in metres and newtons?

I hope I'm being, at least a little, clear. I would like to elaborate a simulation of some interaction using realistic values. For example, I have this circle with one metre radius and a mass of 30 kilograms over which I would apply 50 newtons in a specified direction. Then I just have to set the relation between metres and pixels before rendering it (myself).

Is it possible with matter?

[liabru]

The units are all relative, so as long as you're using consistent scales it should be fine I think.
As you say, first define your scales and then convert all your measurements to it - all that really matters should be the relative proportions.