I always asked why in physics, and more often than not I did not receive or think up an adequate answer.
It's important that you ask why when learning something, and in many circumstances VCE physics doesn't make this possible because often important details are left out to simplify things - but I love the details! The thing is - if you don't ask why early, you'll familiarise yourself enough with the topic you don't fully understand until you think "it's common sense" why such and such is true, whereas really you've just skipped over what could've been a deeper understanding of the topic. Then again, you don't really need to know why at a deep level to get 50 for physics, or spesh.
This occurs with maths at the VCE level too, however it's easier to justify steps yourself, or if you can't do that consulting a more advanced text or some resource online will often do the trick.
So yeah, sometimes I felt physics was ambiguous.