Three copper blocks of masses M_1,M_2 and M_3 kg respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at T_1 ,T_2 ,T_3 (T_1 >T_2 >T_3 ). Assuming there is not heat loss to the surroundings, the equilibrium temperature T is

Q: 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 not heat loss to the surroundings, the equilibrium temperature T is (s is specific heat of copper)

(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) $T = \frac{M)1 T_1 + M_2 T_2 + M_3 T_3}{3(M_1 + M_2 + M_3) }$

(d) $T = \frac{M)1 T_1 s + M_2 T_2 s + M_3 T_3 s }{M_1 + M_2 + M_3 }$

Ans: (b)