Question

Milk with a mass of 0.020 kg and a temperature of 11◦C is added to 0.19 kg of coffee at 86◦C. What is the final temperature? Assume the specific heat capacities of the two liquids are the same as water, and disregard any energy transfer to the liquids’ surroundings. Answer in units of ◦C.

Answer 1

Ans : We know that, Heat Gained = Heat Lost.

Heat Exchange(dQ) = mass(m)*c(specific heat capacity)*dT(change in temperature)

Coffee is at higher temperature, so it looses heat and the milk gains heat.

Specific heat capacities of the two liquids are the same as water ( Let it be "C")

T = Final Temperature

Heat gained by milk = 0.020 .C .(T - 11)

Heat Lost by coffee = 0.19.C.(86 - T)

Heat Gained = Heat Lost

0.020.C.(T-11) = 0.19.C.(86 - T)

Solving this

0.02T - 0.22 = 16.34 - 0.19T

T = 78.8571 Celsius