[填空题]
An ideal gas expands at a cod w 737ydnap)qhe0nx33riu e 8ho,5 tfnstant total preg p906f:edlth ssure of 3.0 atm from 400 mL to 660 mL. Heat then flows out of the gas at constant volume, and the pressu6g:ehlfp 0t9d re and temperature are allowed to drop until the temperature reaches its original value. Calculate
(a) the total work done by the gas in the process, $J$
(b) the total heat flow into the gas. $J$
