Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The rotation of the Earth on its axis from West to East causes the cycle of day and night. One full rotation takes approximately hours.
Shadows change throughout the day due to the relative position of the Sun. Shadows are longest during sunrise and sunset because the Sun is at a low angle, and shortest at noon () when the Sun is directly overhead.
Diurnal animals are those that are active during the day (e.g., humans, dogs, butterflies), while Nocturnal animals are active during the night (e.g., owls, bats, cockroaches).
Crepuscular animals are those specifically active during the twilight hours of dawn and dusk (e.g., rabbits, fireflies).
Plants also follow daily rhythms; for example, the flowers of the Sun-rose (Portulaca) open only in bright sunlight, while the Night-flowering Jasmine (Harsingar) blooms at night and sheds its flowers at dawn.
The temperature of the environment fluctuates in a -hour cycle, typically reaching its maximum in the afternoon ( to ) and its minimum just before sunrise.
📐Formulae
💡Examples
Problem 1:
If the Sun rises at and sets at , calculate the total duration of daylight.
Solution:
Explanation:
From to is exactly hours. From to is an additional minutes. Therefore, the total daylight is hours and minutes.
Problem 2:
At what time of the day will the shadow of a stick be the shortest?
Solution:
Explanation:
At noon, the Sun is at its highest point in the sky (overhead). The angle of the sun rays is nearly vertical, resulting in the minimum shadow length.
Problem 3:
Convert the rotation time of Earth into minutes.
Solution:
Explanation:
Since one rotation takes hours and hour contains minutes, we multiply by to get minutes.