c=4185 J/kgK
V=300 l=0,3 m³
ρ=1000 kg/m³
Qced=m₂c(t₂-Q)
Qprim=m₁c(Q-t₁)
Qprim=Qced<=>m₂c(t₂-Q)=m₁c(Q-t₁) |:c=>m₂(80-40)=m₁(40-12)<=>40m₂=28m₁|:40=>m₂=0,7m₁
ρ=m/V=>m=ρV=1000*0,3=300 kg
m=m₁+m₂=m₁+0,7m₁=1,7m₁=>m₁=m/1,7=300/1,7=176,46 kg
m₂=0,7m₁=0,7*176,46=123,54 kg
V₁=m₁/ρ=176,46/1000=0,17646 m³=176,46 l->apa rece
V₂=m₂/ρ=123,54/1000=0,12354 m³=123,54 l->apa calda