Momentum

physics · motion · force · speed

The heavier and faster. The more massive something is and the speedier it travels, the more momentum it has. A bowling ball rolling slowly has less momentum than a tiny bullet zooming through the air.

Mass times velocity. Momentum is calculated by multiplying an object's mass by its velocity. If you know how heavy something is and how fast it's moving, you can figure out its momentum.

Direction matters too. Momentum is not just about amount, it also has direction. A soccer ball kicked north has different momentum than the same kick heading south, even if the speed is identical.

Harder to stop. Objects with more momentum are trickier to slow down or stop. A truck rolling downhill has way more momentum than a skateboard, so you'd need much more force to bring it to a halt.

Measured in special units. Scientists measure momentum in kilogram-metres per second, which shows the combination of mass, speed, and direction all at once.