Massachusetts Comprehensive Assessment System

2018, High School Intro Physics

Question 32: Open-Response

Reporting Category: Heat and Heat Transfer
Standard: 3.2 - Explain how heat energy will move from a higher temperature to a lower temperature until equilibrium is reached.

A student is investigating heat transfer. The student places the ends of a curved copper bar into two insulated cups, as shown below. The copper bar is at 20°C. Cup 1 contains 40°C water and cup 2 contains 20°C water. Each cup contains the same amount of water.

Describe the direction of heat flow between the cups of water in the first few minutes of the investigation.
Identify the primary method of heat transfer (conduction, convection, radiation) between the cups of water. Describe how the transfer of heat occurred for the method you identified.
After 25 minutes, the water in both cups reaches thermal equilibrium. Explain how the student can determine that thermal equilibrium has been reached between the cups.
On the grid in your Student Answer Booklet, copy the title, axes, and labels of the graph, as shown below. Draw two curves, one to represent the temperature of the water in cup 1 and the other to represent the temperature of the water in cup 2, over a 30-minute period. Assume no heat is lost to the surroundings.

Scoring Guide and Sample Student Work

Select a score point in the table below to view the sample student response.

Score	Description
4	The response demonstrates a thorough understanding of how thermal energy will move from a higher temperature to a lower temperature until equilibrium is reached. The response clearly describes the direction of heat flow between the cups of water, correctly identifies the primary method of heat transfer, and clearly describes how the method of heat transfer occurred. The response also clearly explains how thermal equilibrium is reached and correctly shows a temperature versus time graph.
4
3	The response demonstrates a general understanding of how thermal energy will move from a higher temperature to a lower temperature until equilibrium is reached.
2	The response demonstrates a limited understanding of how thermal energy will move from a higher temperature to a lower temperature until equilibrium is reached.
1	The response demonstrates a minimal understanding of how thermal energy will move from a higher temperature to a lower temperature until equilibrium is reached.
0	The response is incorrect or contains some correct work that is irrelevant to the skill or concept being measured.

Note: There are 2 sample student responses for Score Point 4.

High School Intro Physics

Question 12: Waves and Radiation

Question 23: Motion and Forces

Question 32: Heat and Heat Transfer

Question 44: Motion and Forces

Question 45: Electromagnetism

Return to the MCAS 2018 Student Work Directory

Last Updated: March 14, 2023