Im in highschool and i'd like to be prepared. Are physics useful in becoming a CRNA, in other words do you have to do a unit on it.

CRNA schools do not require high school transcripts, and by the time you're applying it will be 10 years from now, minimum. You'll forget anything you learn in high school. Focus on getting good grades in high school, get into a good college, get good grades in undergrad, pass your boards, get a job. Those should be your priorities.

As prior poster mentioned it is a long road between high school and becoming a CRNA. Though it is good you are thinking ahead!

The first major step to becoming a CRNA is becoming an RN. Look into colleges and universities that offer the BSN degree. Find out what you need to do to be a competitive applicant to their schools and to their programs. (Many 4-year institutions require one application to the school, and a separate application to the nursing program).

Most nursing programs want a solid background in English, Psychology, Algebra, Biology, Chemistry, Microbiology, Anatomy and Physiology. Some may require additional coursework in Communications and statistics. Being familiar with the basics of each subject at the high school level will help make them more approachable if/when you have to study them in college.

Focus on getting good grades in high school, and if you have time participating in sports, music, volunteering, work, or other activities that will help you grow into a well rounded young adult.

Having a base knowledge of physics & chemistry is helpful for the advanced level courses you'll take as a CRNA. But as stated above, graduate schools will not care about your high school transcripts. However, if you have a good science base, it will help you do better in your college level science courses. I've not seen a CRNA program that has a physics pre-req. However, they definitely do want Chemistry (especially organic and biochem) at the collegiate level.

Look at the CRNA programs you're interested in and look at their admissions criteria. They will list all the undergraduate pre-reqs you'll need. That should point you in the right direction.

Best of luck to you