Give two examples of dimension less variables.

Explanation

To solve the question "Give two examples of dimensionless variables," we can follow these steps:

### Step 1: Understand the concept of dimensionless variables
Dimensionless variables are quantities that do not have any physical dimensions associated with them. This means that when you express these variables in terms of fundamental dimensions (like mass, length, time, etc.), they simplify to a value without any units.

### Step 2: Identify the first example
One common example of a dimensionless variable is the **coefficient of friction** (μ).

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