Know that the speed of all electromagnetic waves in: (a) a vacuum is 3.0 × 10⁸ m/s (b) air is approximately the same as in a vacuum

Know that: (a) the Earth is a planet that orbits the Sun once in approximately 365 days (b) the orbit of the Earth around the Sun is an ellipse which is approximately circular (c) the Earth rotates on its axis, which is tilted, once in approximately 24 hours (d) it takes approximately one month for the Moon to orbit the Earth (e) it takes approximately 500s for light from the Sun to reach the Earth