FINAL REPORTCOLOR EFFECTIN THE ABSORPTION OF HEAT

ARZAKHY INDHIRA PRAMESTI

IX 3 / 04LEGALIZATION PAGEBY EXAMINER AND GUIDANCE TEACHER

Examiner

Mr. J. Tri Siswoadji

*Bu Ratna

*Bu Murni

Guidance Teacher

Mr. J. Tri Siswoadji

Mr. Putut SDA

ABSTRACKFront MatterCONTENTS

Legalization page

2

Abstrack

3

Front Matter

Contents

PreliminaryTheory and Hypothesis

Experiment Procedure

Experiment Result

Closing

References

PRELIMINARYBackground

I feel hot when I wear a black or dark shirt in a summer day, and feel more comfortable when I wear a white shirt. I want to know why I feel like that.

Question Why dark color absorb more heat than light color?

How does color absorb heat?

Objective

The goal of this project is to see how the color of an object can absorb different heat when exposed to the sunshine.

Benefit of the Result

We can choose the right color of our clothes if we want to take a walk in a summer day or cold day, dark color or light color. THEORY AND HYPOTHESISTheory

Light is an example of an electromagnetic wave. Electromagnetic waves can travel through the vacuum of interstellar space. They do not depend on an external mediumunlike a mechanical wave such as a sound wave which must travel through air, water, or some solid medium. Electromagnetic waves cover a huge range of frequencies, from high-frequency gamma rays and x-rays, to ultraviolet light, visible light, and infrared light, and on into microwaves and radio waves. As the frequency decreases, so does the energy. The wavelength of an electromagnetic wave is inversely proportional to its frequency. So waves with high frequency have short wavelengths, and waves with low frequency have long wavelengths.

Electromagnetic waves interact with materials in different ways, depending on the nature of the material and the frequency of the electromagnetic wave. Light is the range of electromagnetic waves that are visible (Figure1). For humans, the range of visible wavelengths is from 400 to 700nm (1nm=1109m).

Figure 1. The visible spectrum. X-rays, light, and radio waves are examples of electromagnetic waves. Light is the part of the electromagnetic spectrum that we can detect with our eyes. At the blue end of the visible spectrum, the wavelength of light is shorter (about 400nm). At the red end of the spectrum, the wavelength of light is longer (about 700nm) (Illustration from Abrisa Glass & Coatings, 2005).

This range of wavelengths is called the visible spectrum of light. When you see a rainbow in the sky, or white light that has been refracted through a prism, or diffracted by the regular surface of a CD, you are seeing a spectrum of colors. The different colors are related to the different wavelengths of light. Violet light is at the short-wavelength end of the visible spectrum (400nm), and red light is at the long-wavelength end of the visible spectrum (700nm), with the rainbow of colors in between.

We perceive different colors because our visual system has evolved to make use of the spectral information in reflected light. When light interacts with an object, the light can be absorbed by the object, reflected by the object, or transmitted by the object.For example, when you look at yourself in the mirror, the light that you are seeing has been relected by the mirror, transmitted through the air, through your cornea, through the lens of your eye, and through two layers of cells in your retina before it is absorbed by light-sensitive pigments in your photoreceptor cells. The energy from the absorbed light starts a cascade of chemical reactions in your photoreceptors that ultimately leads to your percpeption: seeing yourself in the mirror.

Objects in the world have different colors depending on which parts of the visible spectrum they absorb, and which parts of the visible spectrum they reflect. Red objects reflect long wavelengths of light (and absorb shorter wavelengths), while blue objects reflect short wavelengths of light (and absorb longer wavelengths). Black objects absorb all visible wavelengths about equally, and white objects reflect all visible wavelengths about equally.

Light that is absorbed by an object is usually converted into heat energy. The goal of this project is to measure how much heat is produced by the absorption of light by different colors. You'll use an incandescent light (a heat lamp), and water-filled jars wrapped with different colors of construction paper. By measuring how much the temperature of the water increases, you'll have a measure of how much light was absorbed by each color.

Before you get started, study Figure2 below and then try to predict what your results will be. The graph compares the spectrum of sunlight with the spectrum of an incandescent bulb. You can see that sunlight has much more energy (brightness) in the range of visible wavelengths (gray shaded region), while the incandescent bulb has more energy in the red and infrared (invisible, longer-wavelength electromagnetic radiation) region of the spectrum.

Figure 2. A comparison of the spectrum of sunlight vs. the spectrum of an incandescent bulb (Schroeder, 2003). The x-axis shows the wavelength (in microns), and the y-axis shows the relative energy (brightness) at each wavelength. The gray region corresponds to the visible region of the spectrum (0.40.7m= 400700nm).

Hypothesis

If I put my cans under the sunshine, the black can will absorb more heat so that its balloon inflates bigger.EXPERIMENT PROCEDUREExperiment Method

Simple experimentVariables

Control

: size of can, color of balloon and duration

Manipulation: color of can

Respond

: absorbed heat

Materials and Equipments 4 soda cans with same size

4 different water colors (black, blue, yellow, white)

4 balloons with same color Timer or clockExperimental Procedure

1. Paint your soda can in different colors, then dried it.

2. Set the balloon in ecah mouth of soda can.

3. Place the can under the sunshine with a distance each other, so that the sunshine can shine directly at the side of a can.

4. Leave the can for a set amount of time (e.g., 5 minutes), and check.

Analyze your results

5. EXPERIMENT RESULTExperiment Result

Color of canDurationBalloon condition before I leaveBalloon condition after I leave

Black3 minutesdeflateddeflated

Blue3 minutesdeflateddeflated

Yellow3 minutesdeflatedinflated

White3 minutesdeflateddeflated

My hypothesis is false. Balloon in the black can didnt inflated, but balloon in the yellow can did. I dont know why.

Discussion

My balloon in the black can didnt inflated, I dont know why, may be because of:1. The paint is too thick

2. The paint is not *rata

3. There was a tiny hole, so the heat came outCLOSINGConclusion

Dark color absorp more heat than lighter color because it absorp more lights energy and changes it into heat.Suggestion

Wear light shirt in sunny day instead of black shirt, so you will not feel hot (REFERENCES

2012. How Does Color Affect Heating by Absorption of Light?. www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p030.shtml.

2012. Why do dark colors absorp heat. http://www.whyzz.com/why-do-dark-colors-absorb-heat. February, 24.

2012. Color and Heat Absorption. http://www.newton.dep.anl.gov/askasci/phy00/phy00156.htm. February, 24.