Jawabanmu

2014-04-15T10:53:12+07:00
Q serap = Q lepas
m x c x delta t = m x c x delta t
1( tc - 90) = 2(60 - tc)
tc - 90 = 120 - 2tc
3 tc= 210
tc=210/3= 70 c

semoga membantu :)

2014-04-15T11:01:51+07:00
Mb.cb(tb-tc)=ma.ca(tc-ta)
2 . 4200. (60-tc) = 1.4200(tc-90)
50400 - 8400tc   = 4200tc - 378000
12600tc    =    882000
tc = 70°c

kalo dalam SI
tc = 70 + 273 = 343 K