A geyser heats water flowing at a rate of 2 . 0 kg per minute from 30 ° C to 70 ° C . If geyser operates on a gas burner, the rate of combustion of fuel will be _____ g min - 1 . [Heat of combustion = 8 × 10 3 Jg - 1 , Specific heat of water = 4 . 2 Jg - 1 C ∘ - 1 ]

Step-by-step solution

Given here, mass flow rate of water, d m d t = 2   kg   min - 1 The geyser heats the water, raising the temperature from θ 1 = 30 ° C to θ 2 = 70 ° C . Total heat utilised in raising the temperature, Δ Q Δ t = d m d t × s Δ θ Δ Q Δ t = 2 60 × 4 . 2 × 40 = m t × L L = heat of combination = 8 × 10 3   J   g - 1 Now, rate of consumption of fuel is m t = 2 × 4 . 2 × 40 60 × 8 × 10 3 = 4 . 2 6 × 10 - 3