zad1dane:m=2,5kgt1=18 stCt2=100 stCcw=4200J/kg *stC
szukane:Q=?
Q=m *cw *(t2-t1)Q= 2,5kg *4200J/kg *stC (100 stC-18 stC)Q=10500 *82 JQ=861000J=861kJ
zad2dane:m=500g=0,5kgQ=1000Jt1=-25 st Ccw=500J/kg *stC
szukane:t2=?
Q= m *cw *(t2-t1) /:m *cwt2-t1=Q/m*cw /+t1t2= (Q :m *cw)+t1t2=(1000J :0,5kg *500J/kg *stC)-25stCt2=4 stC-25stCt2=-21stC
zad3dane:m=100g=0,1kgt1=20 stCt2=100st CQ=2000J
szukane:cw=?
Q=m *cw *(t2-t1) /:m *(t2-t1)c w=Q/ m(t2-t1)c w=2000J/0,1kg *80stCc w=2000 :8 [J/kg *st C]c w=250 J/kg *stC
zad4dane:t1=20 st Ct2=100 st CQ=2MJ=2000 000Jc w=4200J/kg *st Cszukane:m=?Q=m *cw *(t2-t1) /:cw(t2-t1)m= Q /cw (t2-t1)m=2000000J /4200J/kg*stC *80 stCm=2000000 :336000 [kg]m=5,95kg
zad5dane:V=20cm *10cm *5cm=1000cm3=0,001m3t1=20 st Ct2=1540 st Cg(ro)=7800kg/m3c w=500J/kg*st Cszukane:Q=?g=m/V stąd m=V *gQ= V *g*cw (t2-t1)Q=0,001m3 *7800kg/m3 *500J/kg *stC (1540st C-20st C)Q=3900 *1520 [J]Q=5928000J=5928kJ
nikas97