Jawabanmu

2014-01-12T11:34:18+07:00
V = 20 . 10 . 2 = 400 cm³
P =  \frac{m}{V}
m = P . V 
m = 10,5 g/cm³ . 400 cm³
m = 4200 g = 4,2 kg

Δt = 40°C

Q = m . c . Δt
Q = 4,2 kg . 230 J/kg°C . 40°C
Q = 38640 J 

2 5 2