Jawabanmu

2014-05-21T19:15:52+07:00
Dik=
Q=84kj=84000j
m=500gr=0,5 kg
c=4200j.kg.k
t₁=20°C
dit =t₂
jwb=
Q=m.c.ΔT
84000=0,5.4200.(t₂-t₁)
84000=2100(t₂-20)
84000=2100t₂-42000
2100t₂=84000+42000
2100t₂=126000
t₂=60°C
2014-05-21T19:16:31+07:00
Q = 84 kj = 84000
m = 500 g = 0.5 kg
t1 = 20 C
C = 4200J/(Kg.K)
t2 = ?

Δt = Q/m . C
( t2 - t1 ) =  8400/ 0,5 . 4200
( t2 - 20) = 40 
t2 = 40+20
t2 = 60°C