Question_Number,exam_name,subject,Category_Domain,Context,Question,Table_1_Data,Image,Answer
naep_sci_1,naep,science,physical_science,Improve the accuracy of an investigation about conservation of energy,"The student dropped the ball once from each of the four platforms.

How could he improve his experiment to get more accurate results?","[
    {""Platform from Which Ball is Dropped"": ""1"", ""Potential Energy at Platform (joules)"": ""3.0"", ""Kinetic Energy just above the Ground (joules)"": ""2.8""},
    {""Platform from Which Ball is Dropped"": ""2"", ""Potential Energy at Platform (joules)"": ""6.0"", ""Kinetic Energy just above the Ground (joules)"": ""5.4""},
    {""Platform from Which Ball is Dropped"": ""3"", ""Potential Energy at Platform (joules)"": ""9.0"", ""Kinetic Energy just above the Ground (joules)"": ""7.8""},
    {""Platform from Which Ball is Dropped"": ""4"", ""Potential Energy at Platform (joules)"": ""12.0"", ""Kinetic Energy just above the Ground (joules)"": ""10.0""}
]

]",images/2019-12S7_5K136102_c9772f8a84fc11f249504ba264195d25_8_img.webp,"Student response describes a valid way to improve the experiment and explains how this improvement would yield more accurate results.

Major response types include:

- Repeat the experiment (drop the same ball multiple times from each platform) - compare (or average) the results (or data).
- Drop the (same) ball more than once from one or more platforms - average the results for each different platform height.
- Change to volume/mass/density of the ball as follows: Any change to the ball's mass and volume that would result in a higher density (greater mass with smaller volume; same mass with smaller volume; greater mass with same volume) - results in reduction of air resistance (or less energy converted to thermal energy (lost to heat)).
- Use a ball with greater volume and same density (or made of the same material) - results in reduction of air resistance (or less energy converted to thermal energy (lost to heat)).
- Use a ball made with a material that gives it a smoother surface - results in reduction of air resistance (or less energy converted into thermal energy (lost to heat)).
- Perform experiment in an airless environment - results in reduction of air resistance (or less energy converted to thermal energy (lost to heat)).
- Add more platforms - obtain more data points.
- Use better technology to release the ball (or to catch it, time it, etc.) - reduce human error; get more reliable/precise data.

Note:- Non-acceptable responses include: dropping the ball from different angles; changing the heights of the platforms.
- Acceptable synonyms or phrases for ""air resistance"" include: friction; air friction; drag.
- Inadequate or incorrect descriptions of how to change the volume/mass/density of the ball to reduce air resistance include: use smaller (larger) ball; use ball with greater (or smaller) mass.
- Saying ""do multiple trials"" can mean ""repeat the experiment"" or ""drop the ball more than once"" depending on the context of the response. If context is not clear, interpret as ""repeat the experiment."""