You can definitely pass A-School. For me A-school has been the hardest leg of the pipeline for me, (I'm an electrician in prototype now.) but even throughout A-school all I really needed to do was apply myself and show up. The people who failed out didn't typically put everything into it, they got onto a high hours program and gave up. As for no exposure to physics, that would help you out a lot with a-school, but a-school is more about learning how to learn, and pre-existing knowledge only goes so far. They'll give you a lot of information in a short amount of time, so if you can keep up, you're good. I knew a guy from my A-school class who was pretty similar, had an accounting degree, did well in college, worked as an accountant for a while. He was also an auditory/visual learner, and could explain everything to an instructor extremely well and intelligently. Unfortunately, when it came to tests he wasn't as good, he struggled through a-school and power school. When he made it to prototype, where everything is hands on and you can talk through your knowledge with an instructor, he excelled and is now top of his class.
The moral of the story is that if you keep up, and work hard, the instructors at NNPTC will help you get through. People who demonstrate a good work ethic tend to do well in prototype, and especially in the fleet. If you need any more advice feel free to PM me or post here.