G=mg=50kg×10N/kg=500N,跳起一次做的功是:W=Gh=500N×0.05m=25J.每分钟做的功是:W′=120×25J=3000J.每分钟做功的功率是:P= W′ t = 3000J 60s =50W.故答案为:25;50.