# It’s raining

Table of Contents

Keywords

"equacions de primer grau"
"velocitat"
"sector circular"
"capacitat"
"coordenades baricèntriques"
"when"
"conversió d’unitats"
"àrea d’un sector de circumferència"
"angles"
"volum d’un cilindre"
"regla de tres directa - funció lineal"
"mesurar"
"estimar"
"activitats"
"física"

Abstract

How much did it rain? How far is the storm? Can we find how much did it rain from neareast weather stations?

# Act 1

- How far is the storm?
- How much did it rain?

# Act 2

## How much did it rain?

- We put the watering can to filling up
- We obtained these mesures: weight of the water and the volume of the water inside watering can
- Dimensions of watering can: radious (zoom), cover, angle of the cover, length (zoom)
- Can you find how much it rained (in liter per square meter)?

## How much did it rain? bis

- If we know the records of near weather stations, can we estimate how much did it rain in our house?
- In what time this method would not be applicable? How many points (weather stations) do we need to apply this method?
- Can you apply it here?
- Can you estimate how much did it rain in red point? The raw data is available here (file is encoding with
`ISO-8859-14`

).

## How far is the storm?

- Can we find the distance between our house and storm if we know that there is a gap of $n$ seconds between thunder and lightning?
- Speed of light (source wikipedia)
- Speed of sound (source wikipedia)

# Notes

- In “How much did it rain? bis”, we can introduce baricentric coordinates and see that we need at least 3 points to assure the procedure is trustworthy. In this case we get a “geometric mean” of the stations.
- We don’t need to calculate the volume in watering can and infer the volume in one square meter because rainforest volume could be mesured only by the high of the water (local copy)

# About this document

The author of this document is Xavier Bordoy. The first version was created on October 9th 2016. The document was released under the license Creative Commons Attribution 4.0 International (CC BY 4.0).