Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Earth has two types of movements: Rotation and Revolution.
Rotation: The spinning movement of the Earth on its own axis from West to East. The axis is an imaginary line passing through the North and South Poles, tilted at an angle of .
Rotation causes Day and Night. It takes exactly hours (or day) to complete one rotation.
Revolution: The movement of the Earth around the Sun in a fixed elliptical path called an Orbit.
Revolution takes approximately days to complete, which we call a year. The extra day adds up to a full day every years, creating a Leap Year of days.
The Earth's revolution, along with its tilted axis, causes the change in Seasons (Summer, Winter, Autumn, and Spring).
When a hemisphere is tilted towards the Sun, it experiences Summer; when tilted away, it experiences Winter.
📐Formulae
💡Examples
Problem 1:
If the Earth stopped rotating but continued to revolve, what would happen to day and night?
Solution:
The cycle of day and night would change drastically.
Explanation:
Because rotation causes the daily cycle of day and night, if it stopped, one side of the Earth would face the Sun for months (constant day) and the other side would be in darkness for months (constant night) as it moves around its orbit.
Problem 2:
How many hours does the Earth take to complete full rotations?
Solution:
hours.
Explanation:
Since rotation is equal to hours, we multiply the number of rotations by to find the total time.
Problem 3:
Why do we have a Leap Year every years?
Solution:
To account for the extra day in the Earth's revolution.
Explanation:
The Earth takes days to orbit the Sun. We calculate a year as days. To make up the difference, we add the four quarters: full day, which is added to February every years.