Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Universe is a vast space that contains all matter and energy, including galaxies, stars, planets, and moons. Our solar system is a tiny part of the Milky Way galaxy, also known as 'Akash Ganga'.
Celestial Bodies are objects like the Sun, Moon, and stars that shine in the night sky. Stars are huge celestial bodies made of hot gases that emit their own heat and light; the Sun is the nearest star to Earth.
The Solar System consists of the Sun, eight planets, satellites (moons), and other celestial bodies like asteroids and meteoroids. The planets in order of distance from the Sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Earth is the third planet from the Sun and the fifth-largest planet. It is called a 'Blue Planet' because two-thirds of its surface is covered by water. Its unique shape is described as a 'Geoid', which means an earth-like shape (flattened at the poles).
Light Year is the unit used to measure distances in space. It is the distance light travels in one year. Light travels at a speed of approximately .
Asteroids are tiny rocky bodies that move around the Sun, mostly found between the orbits of Mars and Jupiter. Meteoroids are small pieces of rocks which move around the Sun and occasionally enter Earth's atmosphere.
📐Formulae
💡Examples
Problem 1:
Calculate the approximate distance of the Sun from the Earth if light takes to reach the Earth at a speed of .
Solution:
Explanation:
By multiplying the speed of light () by the time taken (), we find that the Sun is approximately away.
Problem 2:
If the average distance of Earth from the Sun is and a certain comet is at , find the difference in distance using vertical subtraction.
Solution:
Explanation:
The difference between the two distances is .