Vectors and Scalars - The Foundation of Motion
Ever wondered why physicists are so fussy about direction? It's because some measurements need it, whilst others don't! Vector quantities have both size (magnitude) and direction - think of force, displacement, velocity, and momentum.
Scalar quantities only have size, no direction needed. These include mass, speed, distance, energy, and time. For example, saying "I walked 100m north" describes displacement (vector), but "I walked 100m" describes distance (scalar).
Here's something that trips many students up: displacement is the straight-line distance between your start and end points, whilst distance is the actual path you travelled. Because of curves and bends, displacement is usually less than the total distance covered.
Quick Check: Weight is a force that always acts towards Earth's centre - that's why it's a vector quantity measured in Newtons!
