Science Common Sense

1714 - What is the relationship between Galileo's law of inertia and Newton's laws of motion?

Galileo's law of inertia and Newton's laws of motion are connected.

Galileo's law of inertia says that an object at rest (not moving) will stay at rest, and an object in motion will keep moving, unless something (a force) acts on it to change its motion.

Newton took this idea and made three laws of motion:

1. The first law (Newton's) is the same as Galileo's law of inertia - it says an object keeps moving or stays still until a force acts on it.
2. The second law says how much a force will change an object's motion (it's about how much force is needed to make something speed up or slow down).
3. The third law says that when you push or pull (apply a force), there's always an equal and opposite reaction (or force) in the other direction.

So, Newton's laws of motion build on Galileo's law of inertia. Galileo started the idea, and Newton expanded on it to explain more about how the world works.