Question

critical thinking...
have you ever been enjoying a cool swimming pool on a hot summer day, but then gotten
out of the pool and experienced sizzling hot concrete underneath your feet?
what are some possible explanations based on the results from the experiment. circle all
that apply
a. the cement heats up faster than the water, so it is hotter than the water.
b. the cement has been heating up for longer than the water.
c. the cement has a low specific heat, therefore heats quickly and will be hotter than the water.
d. the water has a high specific heat, therefore heats slowly and will be cooler than the cement

Explanation:

• Option a: Cement has a lower specific heat capacity than water. According to the formula \(Q = mc\Delta T\) (where \(Q\) is heat absorbed, \(m\) is mass, \(c\) is specific heat capacity, and \(\Delta T\) is change in temperature), for the same amount of heat \(Q\) absorbed (assuming similar mass \(m\) exposure to sunlight), a lower \(c\) (specific heat) means a larger \(\Delta T\) (temperature change). So cement heats up faster than water.
• Option c: Since cement has a low specific heat (\(c\)), using \(Q = mc\Delta T\), with \(Q\) (heat from sun) and \(m\) (assuming comparable mass exposure) being non - zero, a low \(c\) leads to a relatively large \(\Delta T\) (it heats quickly). And water has a high specific heat, so for the same \(Q\) and \(m\), it has a smaller \(\Delta T\) (heats slowly). So cement (with low \(c\)) will be hotter than water (with high \(c\)).
• Option d: Water has a high specific heat capacity (\(c\)). Using \(Q=mc\Delta T\), for a given \(Q\) (heat from sun) and \(m\) (assuming similar mass exposure), a high \(c\) means a smaller \(\Delta T\) (temperature change), so it heats slowly and will be cooler than the cement (which has a low \(c\) and thus a larger \(\Delta T\) for the same \(Q\) and \(m\)).
• Option b is incorrect. Both the cement and the water in the pool are exposed to sunlight (heat source) for the same amount of time during the day (assuming the pool is outdoors during the day).

Answer:

a. The cement heats up faster than the water, so it is hotter than the water.

c. The cement has a low specific heat, therefore heats quickly and will be hotter than the water.

d. The water has a high specific heat, therefore heats slowly and will be cooler than the cement.