A Carnot engine whose high-temperature reservoir is at $620 \mathrm{~K}$ takes in $550 \mathrm{~J}$ of heat at this temperature in each cycle and gives up $335 \mathrm{~J}$ to the low-temperature rescrvoir. (a) How much mechanical work does the cngine perform during cach cycle? What is (b) the temperature of the low-temperature reservoir; (c) the thermal cfficicncy of the cycle?