In central Iowa,which one of the following would yield the highest UV exposure on a sunny day,with a sky clear of all clouds and apparent pollution? Thirty minutes of direct exposure to the sun
A)at 1:00 PM on June 30.
B)at 3:00 PM on September 30.
C)at 9:00 AM on December 1.
D)at 2:00 PM on March 30.

Question

Quizplus · Accepted Answer

UV exposure is the highest when the sun is directly overhead, which occurs at solar noon. As central Iowa is in the northern hemisphere, the highest solar noon occurs during the summer solstice, around June 21. Therefore, 1:00 PM on June 30 will be closer to solar noon and will yield the highest UV exposure. The other options are either too early or too late in the year to have a high solar noon, and the angle of the sun is lower, leading to lower UV exposure.

In Central Iowa,which One of the Following Would Yield the Highest