Ta có: \(Q=mc\left(t-t_1\right)\Leftrightarrow Q=mct-mct_1\)
\(\Leftrightarrow t_1=\dfrac{mct-Q}{mc}=\dfrac{3,5.393.2600-250000}{3,5.393}=2418,25^oC\)
m = 3,5 kg
t2 = 260 oC
Q = 250 kJ = 250 000 J
c = 380 J/Kg.K
giải:
Q = m.c.Δ∆t = > 250 000 = 3,5 . 380 . (260 - t) => t = 72 oC