Algol
The total thermal energy going into the pot and the water to bring the water to a boil may be stated as: Q = Q(pot) + Q(water) The time taken to raise the water to a boil is: t = Q / P t = [Q(pot) + Q(water)] / P Where P is power in watts, the value of Q is equal to mcΔT, so: t = [mcΔT(pot) + mcΔT(water)] / P Here, c is specific heat (for copper its 387J/kg∙°C and for water, 4186J/kg∙°C), m is mass and T is temperature. The mass of the water is 2.6kg (easy conversion from liters). The power is found from: 14000BTU/h = 14000BTU/h(0.293W/1.00BTU/h) = 4100W So for part (a): t = [(0.43kg)( 387J/kg∙°C)(80°C) + (2.6kg)( 4186J/kg∙°C)(80°C)] / 4100W = 220s (rounded, or 3.7min.) (b) In this case, the water changes phase, so for water, use the equation Q = mL (where L is the latent heat of vaporization, water’s is 2.26 x 10^6J/kg). : t = mL(water) / P = (2.6kg)( 2.26 x 10^6J/kg) / 4100W = 1400s (rounded, or about 23 min.) Hope this helps.