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Question
A Bunsen burner raises the temperature of 500g of water from 10°C to 100°C in 5 minutes. What heat is supplied per second?
Solution
m = mass of water = 500 g, θ1 = Initial temperature = 10 °C
c = Specific heat capacity of water = 4.2 J/g °C, θ2 = Final temperature = 100 °C
Let Q be heat supplied by Bunsen burner = Q
Heat lost by Bursen burner = Heat gained by water ...(Law of calorimetry)
Q = mc(θ2 - θ1)
Q = 500 × 4.2 × (100 - 10)
Q = 500 × 4.2 × 90
Q = 189000 J
Heat supplied by burner per second Q = `"Total heat"/"time" = 189000/"300s"`J
= 630 J/s
Heat supplied per second is 630 J/s.
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