Water is capable of carrying approximately _______________ times more heat than an equal volume of air.

Water is capable of carrying approximately _______________ times more heat than an equal volume of air.

• A. 100
• B. 350
• C. 5000
• D. 3500

Answer: (D)

The main idea is thermal mass per volume: how much heat a substance can store per unit volume. To compare how much heat an equal volume can carry, use heat per volume = density × specific heat capacity (at a given temperature range). Water has a density of about 1000 kg/m^3 and a specific heat capacity of about 4.18 kJ/kg·K. That means per cubic meter, water can store roughly 4.18 x 10^6 J per kelvin of temperature change. Air, on the other hand, has a density around 1.2 kg/m^3 and a specific heat capacity near 1.0 kJ/kg·K. So per cubic meter, air stores about 1.2 x 10^3 J per kelvin. Taking the ratio gives roughly 4.18 x 10^6 / 1.2 x 10^3 ≈ 3.5 x 10^3. So water can carry about 3,500 times more heat per equal volume than air. Therefore, the best answer is about 3500.

The main idea is thermal mass per volume: how much heat a substance can store per unit volume. To compare how much heat an equal volume can carry, use heat per volume = density × specific heat capacity (at a given temperature range).

Water has a density of about 1000 kg/m^3 and a specific heat capacity of about 4.18 kJ/kg·K. That means per cubic meter, water can store roughly 4.18 x 10^6 J per kelvin of temperature change.

Air, on the other hand, has a density around 1.2 kg/m^3 and a specific heat capacity near 1.0 kJ/kg·K. So per cubic meter, air stores about 1.2 x 10^3 J per kelvin.

Taking the ratio gives roughly 4.18 x 10^6 / 1.2 x 10^3 ≈ 3.5 x 10^3. So water can carry about 3,500 times more heat per equal volume than air.

Therefore, the best answer is about 3500.