Question

尼

為何壓縮功是負的，我知道題目的敘述功是負的，但對氣體壓縮的功正常來說不是都是正的嗎？

***An ideal gas does 80 J of work when compressed isobarically. The heat given to the gas during this process is:
(Cym= 2.5R) (Hint: w=-PAV for isobaric process )
(A) 700 J (B) 350 J. (C) 280 J (D). 300 J. (E) 2001-
答案:C
w= 80J= -PAV (for isobaric process).
PV=nRT.
PAV-ORAT
AU-n*2.5R* AT-2.5"(PAV)-2.5*80=200J.
AU-q+w-200--80+q-
9-780J.