la
13. What is the~iflerence between heat~~nperature?-
27. (;iven Ihat Ihe melting and fi'eezing tt'ml~ralur(:s of Wal('1
':~ are id(:l1lical, whal del(:rmil1es wh(:lh(:r a mixlur(: 01 iCl
al1d wal(:r will fr(:eze or mclt?
3'4,! A 11(:\\, liqllid i,'i di,'icoy(:r(:d th;lt h.lS Ihe S.lm(: h()iling poil11
--.lJl!1 spl't!fic hl'at a, w;ttl'r \)11! a lat(,'l1l JIl'at of vaporizatioll
of 10 cal<)ries p(:r ~'am, A'~;;umil1g 11;al Ihi,'i I1CW liquid is
sale 10 drink, would it he morc or I(:ss convcnicnt than
\\,at~h()ilil1.l\' e~~~hx? 7. Durin.l\' a process, 28.1 of heat are translcrred into a system,
---while the system itself does 12.1 ofwork. What is the chanKc
in the internal energy?f~e systcm!---
13. Six .l\'rams of liquid x at 35°(: art' addl.'d tI) :J, .l\'rams of liq-
~ uid Val 20°(:. The spccific hcat ()f liquid x is 2 cal/.l\' .°(~,
al1d Ihe ,'ipeci!l{, hl'at of liquid Vis I cal/.l\' .0(:. Ifl',tch .l\'ram
of li()uid X !;i\'cs up t\\'o call);il's to ')iquid \" lillrl th~.
chanKe in temperature of eac~~q~~. --' "
!!:0 How much ht;at would it take to melt a l-k.l\' hl<)ck of icl',
'3.) Why is it not possible to run an ocean liner by taking in sea-
J water at the bow of the ship. extracting internal energy
from the water, and dropping ice CllbeS off the stern?
~:}n an ideal heat engine, 1000 joules of energy are extracted
~-' from the hot region at 800 K. One of the laws of thermo-
dynamics requires that if the cold region is at 320 K, the en-
gine must exhaust 400 joules of energy. Which law of ther-
modynamics requires this?
~-
(5! What input energy is required if an engine performs 300 kJ
of work and exhausts 400 kJ of heat?
~What is the efficiency of a heat engine that does 50 J of
work for every 200 J of heat it takes in?
