High-school Physics? Somewhat difficult if you've never worked anything Physics-related prior to taking the class. If you're adequate with math, maybe up to Pre-Calculus, and have a decent level of analytical reasoning, it shouldn't be too difficult.
There's a few ways to think of it, especially depending on how it's taught. Usually it is either about memorizing equations and rearranging (algebra). This is usually how it is done in high school.
Sometimes they focus more on problem solving methodology. In these cases you will often have a formula sheet, but the questions asked are generally outside of the box and have never been given as a specific example. I would usually get some questions like this if the teacher was fond of the subject they taught and wanted to add some challenge, but most questions were the 1st type.