While it may be helpful, you don't necessarily need to take a particular level of maths to ensure favourable results in Physics. It's not like maths is some sort of co-requisite that must be taken if you wish to perform well in Physics. I believe your decision to take Mathematics Standard is valid.

As far as I'm aware, Mathematics Standard does not cover any concepts that could be beneficial to your studies of Physics. Mathematics Advanced is where I believe some concepts taught may be related (and may therefore be beneficial) to your studies of Physics. Because Mathematics Advanced is the starting point in terms of where calculus is taught (no calculus is taught in Mathematics Standard), it may feature potentially beneficial concepts, knowledge of which may assist you with Physics. The focus on Physics within maths courses increases with Mathematics Extension 1 and, in particular, Mathematics Extension 2.

Mathematics Standard and Physics are 2 separate subjects, meaning that you must not rely on your knowledge in one in an attempt to perform well in the other. Instead, you must ensure you allocate adequate study time for both subjects, allowing you to effectively understand and learn the respective topics/modules/concepts of those subjects.

Alternatively, if you feel that you may be missing out by taking Mathematics Standard, you can always take Mathematics Advanced to experience the course, allowing you to make a more informed decision regarding whether to drop or to keep this subject by the end of year 11.

I hope this helps!