Item WC037003: The temperature of a glass of water left outside in the sun increases more in the middle of the day than in the morning because the angle at which sunlight strikes the earth is different in the middle of the day than in the morning.

Students in several different cities measured how long it takes for the temperature of a glass of water to increase while it sits outside in the sun for 15 minutes. All students found that the temperature of the water increased more when left outside in the middle of the day than when left outside in the morning. Which of the following statements is TRUE about why the temperature of the water increased more in the middle of the day than in the morning?

  1. The sun itself is hotter in the middle of the day than it is in the morning, and the temperature of the sun affects how much the sunlight warms the water.
  2. The earth is closer to the sun in the middle of the day than it is in the morning, and the distance that sunlight has to travel affects how much sunlight can warm the water.
  3. The angle at which sunlight strikes the earth is different in the middle of the day than it is in the morning, and the angle of sunlight affects how much the sunlight can warm the water.
  4. The only reason the temperature of the water increases more in the middle of the day is that the atmosphere blocks more of the sunlight before it reaches the glass of water in the morning than it does in the middle of the day.

Distribution of Responses

Chart showing distrubtion of responses for Item WC037003

Percent of students responding correctly

Overall44%
Grades 6–841%
Grades 9–1250%
Male46%
Female43%
Primary Language is English46%
Primary Language is not English34%

View data table