Scalars
A scalar physical quantity is something that only tells us the magnitude (size) or amount of something, without any information about its direction. It’s like a simple number. For example, think of things like mass, height, temperature, or time.
If I say my mass is 60 kg, that’s a scalar because it only tells you the size of my mass and doesn’t give any direction.
Here are some examples of scalar quantities:
– Distance (how far apart things are)
– Speed (how fast something is moving)
– Mass (how much matter is in an object)
– Temperature (how hot or cold something is)
– Time (how long something takes)
Vectors
Vectors is the physical quantity that have both magnitude (size) and direction.
For example, if I say I walked straight 50 meters north, that’s a vector because it tells you how far I walked (50 meters) and in which direction (north). Vectors are usually represented as arrows, with the length of the arrow showing the magnitude (size) of the vector and the direction showing the direction of the vector.
Examples of vector quantities are:
– Displacement (how far and in what direction an object has moved from its starting point)
– Velocity (the speed and direction of an object’s motion)
– Acceleration (how quickly an object’s speed changes)
– Momentum (how much motion an object has)
– Forces (pushes or pulls on objects)
– Weight (the force of gravity pulling on an object)
In short, scalars are numbers that describe the magnitude (size) of something, while vectors represent both the magnitude (size) and the direction of something.
For instance, distance is a scalar quantity.
If I say Mark walked 2 km today, you know the magnitude (how far) he walked, but you do not know the direction. It’s just about the size, so it’s a scalar quantity.
On the other hand, if I say Mark walked 2 kilometers straight from home to school today, you know both the magnitude (how far) he walked and the direction (from home to school). It includes the size and the direction, so it’s a vector quantity.
If you want to learn more about the difference between Distance and Displacement, or Speed and Velocity, you can watch the video. It will help you understand these concepts even better.