Physics also tends to expect some understanding of calculus... which tends to be a junior or senior level class. Having someone take a physics class when they're still struggling with single variable substitution in equations would be torturous to student and teacher alike.

Science teacher here. Physics First is absolutely not throwing them into the deep end, and should not be the hardest class. Physics First generally means physics taught without calculus, and most of it is stuff that could have been taught to most eighth graders.

Not saying it won't be hard, but I don't want you to think it's some crazy torture. It should be no harder than doing Bio or Chem first, and for many kids it's easier. (Bio and Chem have way more memorization and vocabulary.)

At the high school level of presentation and rigor, Biology is hard and boring full of memorization without anything that reduces or compresses the data. Chemistry is very hard, lots of memorization and also lots of mathematical thinking. Physics is easy, very few basic laws that are quite intuitive and whose proofs you are not expected to learn and links in most directly to real life things you can feel and experience such as levers, moments etc.

In the NL we start with a combined chemistry/physics class that's mostly physics, after the 2nd year you get physics, chemistry and biology as separate classes.

I don't think physics is hardest. On the contrary, physics is probably the best subject to start with, because everyone (even people who don't know about physics) have experienced physics. People intuitively understand that you go faster down a steep hill, than a gently sloped one.

> Most schools do biology > chemistry > physics

I'm only aware of schools providing these three courses as independent of each other. Which makes sense, since they are independent.

I took Chem as a sophomore, Physics as a freshman, AP Chem as a senior, and AP Physics as a senior. I didn't take a single bio course after 7th grade.

For what it's worth, both Calculus courses were harder IMO than any of the aforementioned.

> Most schools do biology > chemistry > physics, which is from funnest and easiest to most technical and hardest

More like from what women prefer to what men prefer, they probably do it since most teachers are women and prioritize what girls want. Physics is "hard" as in not soft, not "hard" as in not easy.

The reasonable order is the opposite, physics underpins chemistry and chemistry underpins biology.