Day

High school (ages 12+)
Environment & Earth

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/day

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the standard duration?Exactly 86,400 SI seconds, though natural variations occur
2. What is the biological significance?Drives circadian rhythms, fundamental to the health and functioning of all organisms
3. Why does Earth spin?Earth spins because of forces from the Sun and Moon and the way its mass is distributed, which can cause small changes in its rotation.
4. How long is a day?A day is defined as exactly 86,400 seconds, but sometimes a leap second is added to keep clocks in sync with the stars.

Diurnal Cycle: The daily cycle of light and darkness caused by Earth's rotation.
Circadian Rhythms: Endogenous biological cycles that regulate physiological processes over approximately 24 hours.
Coordinated Universal Time (UTC): The primary time standard by which the world regulates clocks and time.
Leap Second: An occasional one-second adjustment to UTC to keep it synchronized with astronomical time.