A student measures the temperature change of 0.5 kg of water from 20°C to 40°C. If the specific heat capacity of water is 4180 J/kg°C, how much energy is transferred as heat?

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Multiple Choice

A student measures the temperature change of 0.5 kg of water from 20°C to 40°C. If the specific heat capacity of water is 4180 J/kg°C, how much energy is transferred as heat?

The key idea is that heat energy depends on how much material you have, how easily it heats, and how much the temperature changes. The formula is Q = m × c × ΔT. Here, mass m = 0.5 kg, specific heat capacity c = 4180 J/(kg·°C), and the temperature change ΔT = 40°C − 20°C = 20°C. So the energy transferred as heat is Q = 0.5 × 4180 × 20 = 41,800 J. That matches the given value. The other numbers would require different mass, a different amount of heating, or a different material with a different c. Water’s high c means it stores a lot of energy for a given temperature rise.

The key idea is that heat energy depends on how much material you have, how easily it heats, and how much the temperature changes. The formula is Q = m × c × ΔT.

Here, mass m = 0.5 kg, specific heat capacity c = 4180 J/(kg·°C), and the temperature change ΔT = 40°C − 20°C = 20°C. So the energy transferred as heat is Q = 0.5 × 4180 × 20 = 41,800 J.

That matches the given value. The other numbers would require different mass, a different amount of heating, or a different material with a different c. Water’s high c means it stores a lot of energy for a given temperature rise.

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