Investigatory Project in Physics Iv (Colored Shadows)

I. INTRODUCTION

A shadow can be seen when an object blocks the light. The light wasn’t able to reach the surface. That’s why it appears black. But in fact, not all shadows are black. In only appears that way because only one color is present. In this investigatory project, we have investigated that we can get colored shadows when there are multiple light sources of different colors.

Definition of the study

~Additive color mixing is color created by mixing together light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color system.

~Subtractive color mixing is employed with paints and pigments, in contrast with additive color mixing with colored lights for spotlighting and theatrical lighting.
~Light is a form of electromagnetic energy that moves in wave like patterns.

~Retina is a light-sensitive layer of tissue, lining the inner surface of the eye.

What are expected to be presented in the study?
~We are expected to present an investigatory project which explains how shadows are formed and how to make colored shadows. It also shows how the direct and indirect source of light affects the color of shadows.

Cite an advantage/ benefits that can be derived from the study
The benefits that can be derived from this study is simply our additional knowledge. We’ve learned a lot of things from this study that we didn’t pay attention most of the time. Probably because we always see it in our everyday living such as colors and shadows. The fact that we have learned new information about this study was already the advantage of it.

II. MATERIALS USED
~3 flashlights
~Blue, red, and green cellophane (1 each)
~White cloth/cartolina

III. STEPS/ PROCEDURE USED

~Stick the white cartolina into the wall.
~Turn on one of the flashlights then shine it directly into the wall. ~Block the light using one hand
~Turn on another flashlight. But this time, the one with a different color. ~Shine it directly onto the wall together with the first flashlight. ~Turn on the third flashlight and shine it on the wall together with the first two flashlights. ~Block the light using one hand. Observe the color of shadows.

IV. OBSERVATIONS
We have observed that dark shadow are created when we block the light that is hitting the wall. But if we shine another light(green for example) onto the wall, the light will spread all over the shadowed surface, making it appear green instead of black. If we shine another colored light onto the green shadow, it will mix with that color and will change into another color combination.

V. CONCLUSIONS
We have concluded that with the use of multiple light sources, we are able to create colored shadows. We determine the color combination of the light with the use of additive color mixing. But if we mix all 3 of them together, it becomes white.

VI. LEARNINGS
We have learned that the retina of the human eye was able to perceive more than a million shades of color. When a red light, a blue light, and a green light are all shining on the wall, the wall looks white because these colors stimulate the color receptors of the retina equally.