Thermal Energy

A student plans to conduct an experiment using foam cups, some water, a rock, and a piece of metal.

At first, the rock is placed on a scale, and its mass of 123 grams gets recorded. Then, 123 grams of water get heated on the stove to 100°C. The water is poured into a foam cup, followed by the unheated rock. The temperature of the water is recorded with a thermometer until the temperature appears to stabilize.

In the second part of the experiment, water gets heated on the stove. The water gets poured into a foam cup, and then a piece of metal is added. The temperature of the water is recorded with a thermometer until the temperature appears to stabilize.

The student plans to compare the results from each part of the investigation.

Multiple Choice Question
What do the final temperature readings in the experiment represent?

A.
the average kinetic energy of the particles of matter added to water

B.
the average chemical energy of the particles of matter added to water

C.
the average kinetic energy of the particles of water after the water and the added matter has reached equilibrium

D.
the average chemical energy of the particles of water after the water and the added matter has reached equilibrium

1 answer

The final temperature readings in the experiment represent:

C. the average kinetic energy of the particles of water after the water and the added matter has reached equilibrium.

This is because temperature is a measure of the average kinetic energy of the particles in a substance, and when the system reaches thermal equilibrium, the temperature reflects the average kinetic energy of all particles involved, including the water and the added matter (rock or metal).