For Physical Therapy, your curriculum will cover all the science and math needed. You will most probably earn a few credits in externship.
A minor in Business will help you in long run as you spread your wings and do your own practice. This added skill will surely help as your experience grows with any firm.
Best wishes for success.
As a PT professor for 20 years, serving many years on admission boards, I recommend that no matter what your undergrad degree major is, make sure you meet the prerequisites of the PT schools you are intending to apply to. So, first, identify several PT schools that you want to apply to then go into the school's on-line catalog and see what each particular school requires for admission to PT school. For example, some schools may require a microbiology course or an advanced chemistry but others may not. Just be sure that you use your undergrad elective credits in your major to take any courses outside of those required by your major that you may need to meet the PT prerequisites. And always apply to more than one PT school!
Study hard and good luck...
Enjoy your journey and find ways to keep meaningful connections with your college mates for years to come!
I agree with some of the other advice that has been given that business may be a good minor - you'll learn valuable business basics that will help you in whatever career you choose, and would be helpful if you one day one to open your own practice.
My other advice would be to choose a minor in anything you are passionate about or interested in - a foreign language, a social science, etc. You'll be motivated, learn some valuable information, and potential open up an alternate career path down the line should you choose to do so.
Best of luck to you!