`
`
Question:
Three copper blocks of masses M1, M2, and M3 kg respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at T1, T2, T3 (T1 > T2 > T3). Assuming there is no heat loss to the surroundings, the equilibrium temperature T is
(a) $T=\frac{T_{1}+T_{2}+T_{3}}{3}$
(b) $T=\frac{M_{1} T_{1}+M_{2} T_{2}+M_{3} T_{3}}{M_{1}+M_{2}+M_{3}}$
(c) $T=\frac{M_{1} T_{1}+M_{2} T_{2}+M_{3} T_{3}}{3\left(M_{1}+M_{2}+M_{3}\right)}$
(d) $T=\frac{M_{1} T_{1} s+M_{2} T_{2} s+M_{3} T_{3} s}{M_{1}+M_{2}+M_{3}}$
Solution:
The correct answer is (b)
$T=\frac{M_{1} T_{1}+M_{2} T_{2}+M_{3} T_{3}}{M_{1}+M_{2}+M_{3}}$
.jpg)