Question

Abath contains 100kg of water at 60°C.Hot and cold taps are then turned on to deliver 20kg per minute each at temperatures of 70°C and 10°C respectively. How long will it be before the temperatures in the bath have dropped to 45°C.Assume complete mixing of the water and ignore heat loses.

Answer 1

∑ (mass x specific heat capacity x temp change) = 0

100*c*(45-60)+20*time*c*(45-70)+20(time)*c*(45-10)=0 solve for time