How do gravity and inertia work together in orbital motion?

Gravity and inertia work together in orbital motion to keep a body moving in a curved path around another body.

Gravity is a force that attracts two bodies towards each other. In the context of orbital motion, it is the force that pulls an object, such as a planet or a satellite, towards the centre of the body it is orbiting. This force is always directed towards the centre of the larger body, which in the case of an orbit around the Earth, is the Earth's centre.

Inertia, on the other hand, is the property of an object to resist changes in its state of motion. An object in motion tends to stay in motion, moving in a straight line at a constant speed, unless acted upon by an external force. This is known as Newton's first law of motion.

In orbital motion, these two forces work together to create a balance. The inertia of the orbiting body wants to keep it moving in a straight line, away from the larger body. However, gravity pulls it towards the larger body, preventing it from moving in a straight line. The result is a curved path, or an orbit, around the larger body.

The speed of the orbiting body also plays a crucial role. If the speed is too low, gravity will pull the body towards the larger body and it will crash. If the speed is too high, the body's inertia will overcome gravity and it will fly off into space. But if the speed is just right, the body will continue to fall towards the larger body, but its forward motion will keep it from ever hitting it. This delicate balance between gravity and inertia is what allows planets, moons, satellites and even stars to maintain their orbits.