Write quantities as: *number unit*. Use parentheses when ambigious.

Converting physical quantities

*3 l/s* to *m^3/h*Convert

*10 miles* to *km*Convert

*5 kg*m/s^2*Simplify

*50000 lbs*ft^2/s^3*Simplify

Calculating with quantities

```
// freefall time in vacuum
sqrt(2*
```*10 ft*/1gee)

```
// matrix operations with quantities
A = [
```*1kV/cm, 2kV/cm;
3m/s^2, 4m/s^2*]
A.()

```
// area of a circle with a given radius
(
```*3cm*)^2*pi

```
// corner frequency of an RC filter
1/(2*pi *
```*100 Ohm* * *33 nF*)

```
// battery life under a given load
```*1.2V* * *900 mA*h* / *100mW*

```
// period of a pendulum
2*pi*sqrt(
```*20 cm*/1gee)

```
// range of a car
```*60 l* * (*26 mi/gal*)

The automatic dimensional analysis will help you discover mistakes.

Invalid operations

```
// Error - trying to add incompatible quantities
15 m + 3 s
```