Final answer:
The question is about demonstrating that the observed decrease in coffee level within a cup as it cools is not due to thermal contraction, but rather to escaping air bubbles.
Step-by-step explanation:
The question pertains to the physical phenomenon related to the thermal contraction of liquids, specifically coffee, and the factors that can cause the level of the coffee to decrease as it cools in a cup. In particular, the question asks for a demonstration that the observed decrease in the coffee level is not due to thermal contraction by calculating the decrease in level if 350 cm³ of coffee in a 7.00 cm diameter cup cools from 95°C to 45°C. The implication is that most of the level drop is due to escaping air bubbles, not thermal contraction.
The method to perform such a calculation involves understanding the properties of the liquid and the physical dimensions of the cup. For simplicity, we'll assume the coefficient of linear expansion for coffee is similar to that of water, which is approximately 0.000214 per degree Celsius. We can calculate the change in volume (ΔV) due to temperature change using the formula ΔV = βV0ΔT, where β is the volumetric expansion coefficient, V0 is the original volume, and ΔT is the temperature change.