On Wednesday, September 11, 2019 at 9:06:13 PM UTC+1, David Paste wrote:
Hello,

When writing, for example, "metres per second per second" for
acceleration, it is noted as ms^-2 (where the caret symbolises
the -2 is in superscript).

I understand that, and why, "per second per second" is "seconds
squared", but in the notation, why is it superscript minus 2? Why
not just superscript 2?

If I was ever taught this in maths lessons, the info is no longer
in my head.

Thanks in advance for any help,

David Paste.

because it is *per* second - the inverse, ie

10m
---------------
second * second

1/x == x^-1 in this notation.

Compare, for instance, measuring carpet, which is in meters^2,
ie 'square meters', meters * meters, and not a minus in sight.

HTH
J^n