[填空题]
A “Carnot” refrigerator (the reverse op261u fzv y,emf 9rj4( mqrg b1 r*nee)5eh-o+ ad *qifbpni:7ua Carnot engine) absorbs heat from the freezer compartment at a temperature of - e n4 jd91rea* ifrq:5 +eb7b)rpo(gumhiq-n*17$^{\circ}\,C$ and exhausts it into the room at 25$^{\circ}\,C$.
(a) How much work must be done by the refrigerator to change 0.50 kg of water at 25$^{\circ}\,C$ into ice at -17$^{\circ}\,C$ $ \times10^{4 }J$
(b) If the compressor output is 210 W, what minimum time is needed to accomplish this? s
