I'd say it was a hard A-level question, and I did Physics A-level 20 years ago.You've got to be kidding me?That was GCSE level a few years back (last time I taught it).
I think these days A-level physics isn't allowed to assume you understand calculus (which is ridiculously limiting, of course). Certainly derivatives aren't even on the GCSE mathematics syllabus these days, so I can't see a physics question requiring them being GCSE level.