# FS Rules Quiz Quick Start

This page shows how to use Everything Aero to solve typical  
FS Rules Quiz problems quickly and reliably.

If the problem can be solved with equations, this tool can usually solve it with minimal setup.

---

## Mental Model (Read This First)

Everything Aero is not a step-by-step calculator.

You do not:
- choose formulas manually
- decide calculation order
- worry about solving intermediate variables

You only:
1. Write down what the problem gives you
2. Add any explicit assumptions
3. Tell the solver what you want to find

The solver figures out the rest.

---

## Every Symbol Must Have an Index

Every variable **must** have an index.

Correct:
```
v0 = 30
rho0 = 1.225
```

Wrong:
```
v = 30
rho = 1.225
```

If the problem describes only one condition, always use index `0`.

---

## Typical FS-Quiz Workflow

### Step 1: Write down given values

Copy everything the problem gives you numerically into **Equations**.

Example:
```
v0 = 30
rho0 = 1.225
C_L0 = -3.0
A0 = 1.2
m0 = 280
```

---

### Step 2: Add stated assumptions

If the problem says things like:
- “assume no lateral load transfer”
- “neglect drag”
- “ignore aerodynamic moments”

Input them in **Assumptions**.

Example:
```
W_lat0 = 0
```

Assumptions are treated as **soft constraints** and can be relaxed if needed.

---

### Step 3: Ask the question (optional)

Put exactly what the question asks for into **Looking For**.

Examples:
```
Re0
F_z_total_cornering_fl
v1
```

This tells the solver:
- what to highlight
- what to prioritize if equations conflict

---

## Example 1: Reynolds Number

**Problem**  
A car drives at 30 m/s.  
Characteristic length is 0.3 m.  
Air density is 1.225 kg/m³.  
Dynamic viscosity is 1.8e-5 Pa·s.  
Find the Reynolds number.

### Equations
```
v0 = 30
L0 = 0.3
rho0 = 1.225
eta0 = 1.8e-5
```

### Looking for
```
Re0
```

### Output
$Re_0 = 612500.0$

---

## Example 2: Wind Tunnel Scaling

**Problem**  
A 50% scale model must match Reynolds number of the full car.  
Air properties are identical.  
Full-scale speed is 30 m/s.  
Find tunnel speed.

### Equations
```
Re0 = Re1
L0 = 1.0
L1 = 0.5
v0 = 30
rho0 = rho1
eta0 = eta1
```

### Looking for
```
v1
```

### Output
$v_1 = 60.0$

---

## Final Advice

If you’re unsure:
- Put everything in **Equations**
- Put stated assumptions in **Assumptions**
- Put the question in **Looking for**

Let the solver do the rest.