How much kerosene must be burned to heat 50 liters of water to a boil? The efficiency of the heater is 35%

Formula for calculation: η = Cw * mw * (t – t0) / (qk * mk) = Cw * ρw * V * (t – t0) / (qk * mk) and mk = Cw * ρw * V * (t – t0) / (qк * η).

Variables and constants: Sv – heat capacity (Sv = 4200 J / (kg * K)); ρv – density (ρv = 1000 kg / m3); V – volume (V = 50 l = 0.05 kg); t – temp. boiling (t = 100 ºС); t0 – early. pace. (t0 = 20 ºС); qk is the heat of combustion of kerosene (qk = 4.6 * 107 J / kg); η – heater efficiency (η = 35% = 0.35).

Calculation: mk = 4200 * 1000 * 0.05 * (100 – 20) / (4.6 * 107 * 0.35) = 1.04 kg.