Newton's Laws of Motion

physics · forces · movement · science

Objects stay put. A ball sitting on the ground stays there forever unless you kick it or another force pushes it. Even a moving ball keeps rolling in a straight line until friction, air, or something else stops it.

Force creates change. The harder you push something and the lighter it is, the faster it speeds up. A light tennis ball accelerates more than a heavy bowling ball when you throw them with the same force.

Equal and opposite. When you jump off the ground, you push down on Earth, and Earth pushes up on you with exactly the same strength. That's why you go up instead of Earth going down (Earth is just way too heavy to move much).

Momentum matters. Something moving fast and heavy takes longer to stop than something slow and light. A speeding truck needs way more force to stop than a bicycle because it has much more momentum.

Real world magic. These three rules explain everything from why you wear a seatbelt to how rockets zoom into space to why planets orbit the sun.