A person weighing 80 kg rises to the height of a ten-story building (height 30 m). Using the same energy

A person weighing 80 kg rises to the height of a ten-story building (height 30 m). Using the same energy, 1 liter of water can be heated …

To find the magnitude of the change in temperature of 1 liter of water, we will use the equality: mh * g * h = Q (energy) = Sv * ρw * V * Δt and Δt = m * g * h / (Sv * ρw * V).

Constants and variables: mh – human weight (mh = 80 kg); g – acceleration due to gravity (g ≈ 10 m / s2); Sv – specific heat (Sv = 4200 J / (kg * K)); ρw – density of heated water (for fresh ρw = 1000 kg / m3); V – volume (V = 1 l = 1 * 10-3 m3).

Calculation: Δt = m * g * h / (Sv * ρw * V) = 80 * 10 * 30 / (4200 * 1000 * 1 * 10-3) ≈ 5.7 ºС.

Answer:   1 liter of water can be heated by 5.7 ºС.