Question

To get an idea of how much thermal energy is contained in the world's oceans, estimate the heat liberated when a cube of ocean water, 3 km on each side, is cooled by 4 K. (Approximate the ocean water as pure water for this estimate.)

Answer 1

Q = 4.52 10¹⁷ J

Step-by-step explanation:

Thermal energy can be calculated with

Q = m c_{e} ΔT

in this case it indicates that we approximate seawater to pure water with

c_{e} = 4186 J/ kg K

with the density

ρ = m / V

m = ρ V

V = L³

we substitute

m = ρ L³

Q = ρ L3 c_{e} ΔT

calculate

Q = 1000 (3 103) 3 4186 4

Q = 4.52 10¹⁷ J