Temperature change time base problem.?

Question

Temperature change time base problem. Suppose V = 24 V, I = 0.2 A, mw = 50 gm, cw = 4.18 J/gm�K, mr = 10 gm, and cr = 3.7 J/gm�K. If the water is initially at room temperature, how long will it take for the water to heat up 2 �K?

Answer 1

Assuming no losses,
t = 2(50*4.18 + 10*3.7) / (2.4*0.2)
t = 1,025 s = 17 m 5 s