Massachusetts Comprehensive Assessment System

2018, High School Intro Physics

Question 23: Open-Response

Reporting Category: Motion and Forces
Standard: 2.2 - Interpret and provide examples of how energy can be converted from gravitational potential energy to kinetic energy and vice versa.

The figure below shows a shelving system with four levels. The height of each level is shown in the diagram, and four locations are labeled W, X, Y, and Z.

A person places an object on the shelves.

At which location on the shelves (W, X, Y, or Z) would the object have the most gravitational potential energy? Explain your answer.

A book with a mass of 0.21 kg is placed at location X. A magazine with a mass of 0.11 kg is placed at location Y.

Does the book or the magazine have more potential energy? Show your calculations and include units in your answer.

A 2.5 kg object is placed at location X where it has 10 J of potential energy. A person bumps the shelf, causing the object to fall to the ground.

Assuming air resistance is negligible, explain how conservation of energy is demonstrated as the object falls to the ground.
Calculate the speed of the 2.5 kg object just before it hits the ground. Show your calculations and include units in your answer.

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 energy can be converted from gravitational potential energy to kinetic energy and vice versa. The response correctly identifies the location with greatest gravitational potential energy and clearly explains the answer. The response correctly determines whether the book or magazine has more potential energy. The response also clearly explains how conservation of energy is demonstrated as the object falls to the ground and correctly calculates the speed of the object just before it hits the ground.
4
3	The response demonstrates a general understanding of how energy can be converted from gravitational potential energy to kinetic energy and vice versa.
2	The response demonstrates a limited understanding of how energy can be converted from gravitational potential energy to kinetic energy and vice versa.
1	The response demonstrates a minimal understanding of how energy can be converted from gravitational potential energy to kinetic energy and vice versa.
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: September 28, 2023