When a system is taken from state `i` to state `f` alone the path iaf, it is found that `Q=50` cal and `W=20` cal. Along the path ibf, `Q=36` cal (figure) (a) What is `W` along the path ibf ? (b) If `W=-13` cal for the curved return path `f i`, what is `Q` for this path ? (c) Take `U_(i)=10` cal. What is `U_(f)`? (d) If `U_(b)=22` cal, what is `Q` for the process in and for the process bf ?

Answer

A, B, C, D

Explanation

(a) `DeltaU=Q-W=` same for both paths `W_(ibf)=36-(50-20)=6`cal
(b) Q curved `-(-13)=-(50-20)` Q curved `=-43` cal
(c) `U_(f)=U_(i)+30=40` cal
(d) `Q_(ib)=W_(ib)+DeltaU_(ib)=6+(22-10)=18` cal
`Q_(bf)=Q_(if)-Q_(ib)=36-18=18` cal