Introduction

This project was done by Alexia Caram, Raphaela Altit, Felipe Fraga, Gustavo Kemp and Eduardo Semedo. The topic designated was The Beach and from this we decided to do our project about Surfing. We hope all of you enjoy and appreciate our hard work.

Physics: surfboard motion

In our project, we produced small-modeled surfboards made from polyester. The aim of the experiment was to predict and check which type of surfboard moves faster in a water tray due to waves oscillations pushing them. The proposal was to produce surfboards with different number of fins, and different width and length in order to check how these factors affect the surfboard motion
5 surfboards were produced:
• A surfboard with with no fins was made in order be the control model for the experiment, where it has no alterations in it
• A surfboard with three fins
• A surfboard with a thicker width and 2 fins
• A surfboard with a thicker length and 1 fin
The ideal number of fins for a surfboard is three. The fins are essential to give speed and direction to it. So the surfboard with three fins, and two fins are predicted to move faster than the surfboard with one fin
The width and length of a surfboard is crucial to give It speed. Therefore the surfboard with a higher value for thickness and length is predicted to move faster than the others.

Biology: Investigating the Human eye

For biology Raphaela Altit and Eduardo Semedo will be investigating how the human eye functions, due to different stimulus while practicing surf.
Raphaela will look at how the iris and the pupil work together, controlling the amount of light that enters the eye. While practicing surf, depending on the weather and the period of the day, we will be exposed to different light intensities.
Eduardo will be investigating the processes know as accommodation, when the ciliary muscle contracts or relaxes to change the shape of the eye lens so that we see in the right focus. When a wave is near or far from a person, the shape of the lens changes, so that we see in the correct focus.


For the biological part of the experiment, two aspects of the eye will be investigated. Raphaela Altit was in charge of finding out about the pupil reflex.


The change in size of the pupil is controlled by involuntary contraction and dilatation of the iris, to regulate the light entering the eye and reaching the retina (back part of eye, as shown in diagram below).

In bright light, the pupil will decrease in size, to allow less light to enter, so that the sensitive cells in the retina are not damaged. When the lights are dimmed, the pupil increases in size, thus increasing the amount of light entering the eye and reaching the retina. This change in size is also shown in one of the diagrams below.


In the sunlight, the pupil can be of a very small size, reaching 1.5mm in diameter, and when the lights are down, it can increase a lot, reaching 8mm.


For the Group 4 experiment, the 3D model of the eye will be used to show where the pupil is, and where the iris and the muscles that contract to control the pupil’s size are found in the eye. We will also show where the retina is, to show where the light would damage the eye if it reached it with a greater intensity then what is adequate.

Diagram of the eye, showing all parts.

Change in size of the pupil depending on the light intensity

Chemistry: Surfwax

For the chemistry part of our experiment we will investigate surf wax. We will test two different types of wax, Sticky Bumps and 3e both a waxy solid white wax. Surfboard wax is composed of paraffin and beeswax, often different smells are added to it to make it more attractive.  A wax is an alkane, with heavy molecules C₂₀H₄₂ to C₄₀H₈₂.

Surf wax is important when surfing so the surfer is able to stand and stay upright on the board. The use of wax is according to personal preference and environment so for example there will be specific wax for cold and warm seas.  Petroleum jelly can be added to the composition of surf wax to make it softer and therefore be ideal for cold water, whilst for tropical water the ideal would be the hardest wax.

The experiments done carried out the following way:

1)       0.5 grams of each; Sticky Bumps and 3e were put inside six different beakers (three for each wax). All beakers had 25 ml of a substances; either water, alcohol or cyclohexane. Each wax was tested once with each of these three. With water and alcohol both waxes didn’t dissolve, however with cyclichexane they did. Sticky Bumps started dissolving in cyclichexane with 1.24 minutes and after five minutes became really milky, whilst  3e only after 5 minutes dissolved, but became less milky than Sticky Bumps.

This shows that waxes are not soluble in water and that is why it is used for surfing. Also that it does not dissolve in alcohol, so to remove it from the surfboard a wax comb, which usually comes together with the wax when bought, should be used. The only chemical that dissolved the wax was cyclichexane, a highly flammable liquid with a detergent-like odor used as a nonpolar solvent for chemical industries. Therefore the best way of removing the old wax from the board is definitely with a wax comb !

2) 0.5 grams of both Sticky Bumps and 3e were put into separate test tubes and both inside a large beaker filled with water and it was heated. Each test tube had its own thermometer, which was used to record the temperature when the wax first started to melt. Sticky Bumps melted before at 48 ⁰C after 5 minutes and 3e melted at 52 ⁰C after 6 minutes. This means that both wax have melting point very close, which means they were probably made to be used in seas with the same range of temperature. 

Video on how to do a surfwax: http://www.youtube.com/watch?v=f095SU8GIIo

Bibliography:

 http://en.wikipedia.org/wiki/Paraffin

http://en.wikipedia.org/wiki/Surfboard_wax

http://www.surfing-for-girls.com/surfboard-waxing.html