### Introduction

Light is reflected differently from various surfaces and colors. An understanding of these differences is useful in choosing colors and materials for clothing, in choosing colors for cars, and in city planning. Astronomers use reflectivity differences to help determine characteristics of planets. In this experiment, you will be measuring the percent reflectivity (albedo) of various colors. You will measure reflection values from paper of various colors using a computerinterfaced Light Sensor and then compare these values to the reflection value of aluminum foil. The aluminum foil will arbitrarily be assigned a reflectivity of 100 percent. You will then calculate percent reflectivity using the relationship

$\% {\text{ Reflectivity}} = \frac{{{\text{value for paper}}}} {{{\text{value for aluminum}}}} \times 100$

### Objectives

In this experiment, you will

• Use a Light Sensor to measure reflected light.
• Calculate percent reflectivity of various colors.
• Make conclusions using the results of the experiment.