Jawabanmu

2014-03-14T18:16:03+07:00
Dik : Q= 84 kj = 84000 J
m = 500 g
c = 4200
t1 = 20
Q =m.c.delta t
84000 = 500.4200. delta t
84000 = 2100000 . Delta t
delta t = 2100000 / 84000
delta t = 25

Delta t = t2-t1
25 = t2-20
25 + 20 = t2
45 =t2
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