Understanding Forces and Their Effects
Forces are simply pushes or pulls that can make things move, stop, or change direction. You encounter them constantly - from the engine thrust that propels a car forward to the gentle push you give a door to open it.
When objects move through fluids like air or water, they face air resistance and upthrust. Air resistance works against moving objects (think about sticking your hand out of a car window), whilst upthrust is the upward force in water that helps things float. This is why boats don't sink and why swimming feels easier than you'd expect.
Friction occurs when surfaces rub against each other - it's what stops you sliding about when you walk. Smoother surfaces create less friction, which is why ice skating works so well. On the flip side, gravity constantly pulls objects towards Earth, creating what we call weight.
💡 Remember: Forces can act on objects whether they're moving or completely still - even when you're sitting in a chair, multiple forces are working on you!
The key difference between vectors and scalars is that vectors have both direction and magnitude (like velocity), whilst scalars only have magnitude (like speed). This distinction becomes crucial when calculating how forces combine and affect motion.