1. Gravity: The sun's immense mass exerts a gravitational pull on the planets, drawing them inwards. This force is the primary driver of the orbital motion.
2. Inertia: Planets, due to their constant motion, tend to travel in a straight line. This is known as inertia. Inertia acts as a counterforce to gravity, preventing the planets from falling directly into the sun.
Here's how they work together:
* Gravity: The sun's gravity pulls the planet towards it, trying to make it fall.
* Inertia: The planet's motion due to inertia wants to keep it moving in a straight line, away from the sun.
The balance between these two forces results in a curved path - an orbit - where the planet continuously falls towards the sun but never actually reaches it.
