Explain · Like I'm five version
Newton's laws of motion in terms of a supermarket trolley
A supermarket trolley is the best way to understand how things move.
The first rule of motion is that a trolley likes to stay exactly where it is. If it is sitting still near the freezer section, it will stay there forever unless you push it. Once you start moving down the aisle, it will keep rolling in a straight line until you use your muscles to stop it or steer it into a pile of cereal boxes. An object in motion stays in motion because it is just having a lovely time rolling along.
The second rule is all about how hard you have to push. If your trolley is empty, a little nudge makes it zoom off towards the bread. But if you fill it up with heavy tins of beans and six packs of milk, it becomes very stubborn. You have to push much harder to make a heavy trolley speed up compared to a light one. The more stuff you pile inside, the more work your arms have to do to get it moving quickly.
The third rule is about what happens when you bump into things. If your trolley hits a solid wall, the wall pushes back on your trolley with the exact same amount of force. This is why you feel a bump in your hands when you crash into the dairy shelf. Every action has an equal and opposite reaction, which is a very polite way of saying you should probably watch where you are going.
Where the analogy breaks downA trolley eventually stops due to friction and a wobbly wheel, whereas objects in space can keep moving forever without any help.