I don't think your appendix can explode because you ate too much honestly. It's not even possible to eat so much that your appendix explodes, and if you're feeling any pain it definitely isn't because your appendix is about to explode, believe me. Also you could just type it into the internet, that'd be a much faster solution.
Power is the rate work done given by dividing work done by unit time. It is measured in watts equivalent to J/s. In this case the force by the student is mg = 490 N (taking g as 9.8m/s²) Work done is given by force × distance, Therefore, Power =(force × distance)/ time, but velocity/speed =distance/time Thus, Power = force × speed/velocity = 490 N × 1.25 = 612.5 J/S (Watts) Hence, power will be 612.5 Watts.