What is Newton’s First Law of Motion?

Newton’s First Law of Motion is all about why things keep moving, or don’t, when nothing touches them.

Imagine you're on a swing. You’re going back and forth, having the time of your life. Now, what happens if someone stops pushing you? You’ll still keep swinging for a while, right? That’s because you want to keep moving, just like a toy car keeps rolling when you let go of it on a flat floor.

If nothing is touching something, it won’t change its motion. That means if you're sitting still and no one pushes you, you’ll stay put, just like your little brother who’s napping in his blanket fort. But if something does touch it, like a push, a pull, or even the ground, that thing will start moving, stop, or change direction.

This law is also called the Law of Inertia. Inertia is just a fancy word for “the tendency to keep doing what you’re already doing.” So whether you're zooming on your bike or sitting quietly in your favorite chair, you’ve got inertia working for you, and sometimes against you! Newton’s First Law of Motion is all about why things keep moving, or don’t, when nothing touches them.

Imagine you're on a swing. You’re going back and forth, having the time of your life. Now, what happens if someone stops pushing you? You’ll still keep swinging for a while, right? That’s because you want to keep moving, just like a toy car keeps rolling when you let go of it on a flat floor.

If nothing is touching something, it won’t change its motion. That means if you're sitting still and no one pushes you, you’ll stay put, just like your little brother who’s napping in his blanket fort. But if something does touch it, like a push, a pull, or even the ground, that thing will start moving, stop, or change direction.