✅ 1. What is a Scalar?
A scalar is a single number that represents quantity only.
It does not have direction.
It is not a list.
✔️ Key idea:
A scalar tells you “how much” of something.
📘 Examples of Scalars
| Scalar | What it represents |
|---|---|
7 |
7 apples, 7 meters, 7 dollars |
-3 |
A temperature of −3°C |
0.5 |
Half a unit of something |
100 |
100% |
These are all single numbers, so they are scalars.
✅ 2. What is Magnitude of a Scalar?
The magnitude of a scalar is simply the absolute value of that number.
Magnitude = how big the number is, ignoring whether it is positive or negative.
✔️ Key idea:
Magnitude of a scalar = absolute value = |scalar|
📘 Examples of Scalar Magnitude
Example 1
Scalar: 5
Magnitude: |5| = 5
➡️ The number is already positive, so magnitude is the same.
Example 2
Scalar: -5
Magnitude: |-5| = 5
➡️ We ignore the negative sign because magnitude means “size,” not direction.
Example 3
Scalar: 0
Magnitude: |0| = 0
➡️ Zero has no size.
Example 4
Scalar: -12.5
Magnitude: |-12.5| = 12.5
🎯 Summary
| Term | Definition | Example |
|---|---|---|
| Scalar | A single number that shows a quantity. |
8, -3, 4.2
|
| Magnitude of a scalar | The size of that number; its absolute value. | Scalar = -8 → Magnitude = 8
|
If you want, I can now explain:
🔹 What is a vector magnitude?
🔹 Scalars vs Vectors (side-by-side comparison)?
🔹 Simple pictures to differentiate them?
Tell me and I’ll continue!
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