E=Fs=mgs=0.2kg*10N/kg*0.1m=0.2JP=E/t=0.2J*60s/120s=0.1W
E=W=Gh=0.2kgx10n/kgx0.1m=0.2JP=w/t=0.2Jx60/120s=0.1w注意公式中的对应关系