Final answer:
To determine the mass of ice needed to keep the tent 12°F cooler, we can use the concept of specific heat and the formula Q = mcΔT. By calculating the heat gained by the tent and rearranging the formula, we find that the mass of ice needed is approximately 0.3267 kg (or 0.72 lbs).
Step-by-step explanation:
To determine the mass of ice needed to keep the tent 12°F cooler, we can use the concept of specific heat. The formula for specific heat is Q = mcΔT, where Q is the amount of heat transferred, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature. In this case, we know the change in temperature (12°F) and we want to find the mass of ice. We can assume that the specific heat capacity of ice is 2.09 J/g°C.
First, we convert the change in temperature from Fahrenheit to Celsius. ΔT = (12°F - 0°F) × (5/9) = 6.67°C.
Next, we can rearrange the formula to solve for mass: m = Q / (c × ΔT).
Since we want to keep the tent 12°F cooler, the amount of heat transferred is equal to the heat gained by the tent, which can be calculated using the formula Q = mcΔT. Assuming the room temperature is 72°F, the change in temperature is 12°F, and the specific heat capacity of air is approximately 1.01 J/g°C.
Plugging in the values, we get Q = mcΔT = (m × 1.01 J/g°C × 12°F) = 12.12 m.
Simplifying the equation, we now have m = Q / (c × ΔT) = 12.12 m / (2.09 J/g°C × 6.67°C) ≈ 0.3271 m.
To convert from mass to pounds, we can use the conversion factor of 1 pound = 453.592 grams. Therefore, the mass of ice needed is 0.3271 m × 453.592 g = 148.23 grams.
Answer: The mass of ice needed to keep the tent 12°F cooler is approximately 0.3267 kg (or 0.72 lbs).