Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Earth is a sphere that spins on an imaginary line called an axis, which runs from the North Pole to the South Pole.
The Earth's axis is not straight; it is tilted at an angle of approximately .
Rotation is the movement of the Earth spinning on its axis. One full rotation takes exactly hours, which represents one day.
The Earth rotates from West to East. This causes the Sun to appear to rise in the East and set in the West.
Day and Night occur because the Earth is opaque. At any time, the side facing the Sun experiences day, while the side facing away experiences night.
Shadows change throughout the day. They are longest in the early morning and late afternoon when the Sun is low, and shortest at noon ( PM) when the Sun is at its highest point.
📐Formulae
💡Examples
Problem 1:
If the Earth rotates every hour, how many degrees does it rotate in hours?
Solution:
Explanation:
To find the total rotation, we multiply the degrees per hour by the number of hours elapsed.
Problem 2:
A student notices that at AM their shadow is very long. By PM, the shadow has become much shorter. Why does this happen?
Solution:
The Sun's position in the sky has changed due to Earth's rotation.
Explanation:
In the morning, the Sun is low on the horizon, creating a long shadow. At noon, the Sun is nearly overhead, so the light hits the student from a steeper angle, creating a shadow.
Problem 3:
If it is currently PM (noon) in London, what is the environment like on the exact opposite side of the world?
Solution:
It is AM (midnight) and dark.
Explanation:
Because the Earth is a sphere, only half can face the Sun at a time. The opposite side is in the Earth's own shadow, experiencing night.