Jawabanmu

2014-01-23T17:31:04+07:00
M.c.Δt = m.c.(t2-t1)
84 Kj= 0,5kg × 4200 × (t2-20)
(t2-20)=  \frac{2100}{84} (84Kj-nya pindah ruas)
t2-20=25
t2=20+25
t2=45
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