How many degrees will water weighing 10 liters cool if it gives off 2 mega joules of heat?

Data: V (volume of water taken) = 10 l (10 * 10 ^ -3 m3); Q (the amount of heat that water must give off) = 2 MJ (2 * 106 J).

Reference values: ρ (density of cooled water) = 1000 kg / m3; С (specific heat capacity of water) = 4200 J / (kg * ºС).

The change in water temperature during the release of 2 MJ of heat is expressed from the formula: Q = C * m * Δt, whence Δt = Q / (C * m) = Q / (C * ρ * V).

Calculation: Δt = (2 * 10 ^ 6) / (4200 * 1000 * 10 * 10 ^ -3) = 47.62 ºС.

Answer: The water will cool down by 47.62 ºС.