Question

during an investigation, a student places two water containers inside an insulated cooler at different temperatures. the goal is to observe how the temperatures change over time until they equalize. however, the temperatures of the two containers do not fully stabilize. this suggests that the system is not fully closed. which step could have improved the accuracy of the results by ensuring that the system remained a closed setup? increasing the water volume to slow temperature changes stirring the water regularly to mix the temperatures using thicker - walled containers to reduce heat transfer sealing the cooler completely to block air exchange

Explanation:

A closed - system setup in heat - transfer experiments requires preventing heat loss or gain from the external environment. Sealing the cooler completely blocks air exchange, which is a major pathway for heat transfer between the system and the surroundings. Increasing water volume affects the rate of temperature change but not the system's closed - nature. Stirring the water mixes internal temperatures but doesn't make the system more closed. Using thicker - walled containers reduces heat transfer through the containers but air exchange can still occur.

Answer:

D. Sealing the cooler completely to block air exchange