The programs aren't going to compare notes. If the question is the same and your answer is the same for both schools, then the same essay is fine.
I think MomofMod makes a good point, though. In the college/SA application process, there are lots of essays. The questions can be similar but may not be identical and the answers may differ depending on who asks the question. Thus, as you progress through the process, be sure to assess and answer each question/topic on its own merits and resist the urge to "cut and paste." I can tell you that those who read LOTS of essays, such as SA Admissions, nom committees, etc., can tell whether something was "borrowed" or" re-purposed." It's allowed as long as it's still your own work -- but suggests laziness, lack of attention to detail, etc.