How much pine wood do you need to burn to heat 10 liters of water from 10 (degrees Celsius) to a boil?

How much pine wood do you need to burn to heat 10 liters of water from 10 (degrees Celsius) to a boil? Specific heat of water = 4200J / kg gr.cell., Specific heat of combustion of pine wood = 1.3 * 10/7 J / kg

V = 10 L = 0.01 m ^ 3.

ρ = 1000 kg / m ^ 3.

t1 = 10 ° C.

t2 = 100 ° C.

С = 4200 J / kg * ° C.

q = 1.3 * 10 ^ 7 J / kg.

md -?

To heat water, you need the amount of heat Q, which is determined by the formula: Q = C * ρ * V * (t2 – t1).

When burning firewood, heat Q is released, which is determined by the formula: Q = q * md.

C * mw * (t2 – t1) = q * md.

md = C * ρ * V * (t2 – t1) / q.

md = 4200 J / kg * ° C * 1000 kg / m ^ 3 * 0.01 m ^ 3 * (100 ° C – 10 ° C) / 1.3 * 10 ^ 7 J / kg = 0.29 kg.

Answer: md = 0.29 kg.