Questions: Specific Heat Capacity

Question 1

Why does sand on a beach get much hotter than the ocean water on a sunny day?

• A. The sun shines more on the sand
• B. Sand absorbs more sunlight than water
• C. Sand has a lower specific heat than water, so it heats up more with the same energy
• D. Water reflects all sunlight

Answer: (C)

Sand has a much lower specific heat than water. The same solar energy causes a much larger temperature increase in sand than in water.

Question 2

Water has a higher specific heat capacity than most common materials.

• T. True
• F. False

Answer: True

Water's specific heat (4,186 J/kg·°C) is among the highest of common substances, which is why it is effective as a coolant and why it moderates climate near coastlines.

Question 3

What does it mean to say that copper has a specific heat of 385 J/kg·°C?

Model answer: It takes 385 joules of energy to raise the temperature of 1 kg of copper by 1°C.

Specific heat tells you exactly how much energy per kilogram is needed per degree of temperature change. Copper's low value means it heats up quickly compared to water.