4
advanced-mathA coffee cools from 95°C to 59.38°C in 10 minutes. If cooling is exponential with decay factor 0.9 per minute, what is the room temperature (asymptote)?
A
20°C
B
0°C
C
25°C
D
30°C
Correct Answer: A
Choice A is the correct answer. Use the shifted exponential model.
- Model: .
- Given: , , .
- Set up: .
- Solve: , so:
💡 Strategic Tip: The horizontal asymptote represents room temperature in cooling problems.
Choice B is incorrect because room temperature isn't freezing. Choice C is incorrect because this doesn't match the calculation. Choice D is incorrect because this is too warm.