A backpacker wants to carry enough fuel to heat 2.9 kg of water from 24 ∘C to 100.0 ∘C.

Question

A backpacker wants to carry enough fuel to heat 2.9 kgof water from 24 ∘C to 100.0 ∘C. If the fuel he carries produces 36 kJ of heat per gram when it burns, how much fuel should he carry? (For the sake of simplicity, assume that the transfer of heat is 100 % efficient.) Express your answer using two significant figures

Answer 1

Q = mc(T₂ - T₁)

Q = (2.9 kg) x (1000 g/1 kg) x (4.18 J/g*^oC) x (100 ^oC - 24 ^oC)

Q = 921272 J

921272 J x (1 kJ/1000 J) x (1 g/36 kJ) =

2.6 x 10¹ g