To determine which substance heats up the slowest when exposed to sunlight for the same amount of time, we need to compare their specific heat capacities. The specific heat capacity is the amount of heat required to raise the temperature of a unit mass of the substance by one degree Celsius. A higher specific heat capacity means that the substance will absorb more heat without a significant rise in temperature, hence it will heat up slower.
Here’s the given specific heat data for each substance:
- Brick: [tex]\( 0.9 \, \frac{J}{g \cdot °C} \)[/tex]
- Dry soil: [tex]\( 1.26 \, \frac{J}{g \cdot °C} \)[/tex]
- Paper: [tex]\( 1.336 \, \frac{J}{g \cdot °C} \)[/tex]
- Water: [tex]\( 4.18 \, \frac{J}{g \cdot °C} \)[/tex]
To find which substance heats up the slowest, we look for the substance with the highest specific heat capacity, as it will require the most heat to increase its temperature.
Comparing the values:
- The specific heat capacity of brick is [tex]\( 0.9 \, \frac{J}{g \cdot °C} \)[/tex]
- The specific heat capacity of dry soil is [tex]\( 1.26 \, \frac{J}{g \cdot °C} \)[/tex]
- The specific heat capacity of paper is [tex]\( 1.336 \, \frac{J}{g \cdot °C} \)[/tex]
- The specific heat capacity of water is [tex]\( 4.18 \, \frac{J}{g \cdot °C} \)[/tex]
We see that water has the highest specific heat capacity at [tex]\( 4.18 \, \frac{J}{g \cdot °C} \)[/tex]. This means water will absorb the most heat for a given increase in temperature compared to the other substances, thereby heating up the slowest.
Therefore, the correct answer is:
A. water
