[填空题]
A gas is enclosed in a cylinder fitted a/z*1memjdxp 9 )ad8 jwith a light p c7.3ar62 gi0bk-jz qkts fm6frictionless piston and maintained at atmosphmk. 7a-36tb2fsg q0kjcp zr 6ieric pressure. When 1400 kcal of heat is added to the gas, the volume is observed to increase slowly from $12m^3$ to $18.2m^3$ Calculate
(a) the work done by the gas . $ \times10^{5 }$
(b) the change in internal energy of the gas. $ \times10^{ 6}$
