Results

There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation.

Video 1: What are frequency polygons?
Video 2: Examples of frequency polygons
Video 3: Further examples of frequency polygons

By the end of this unit you will be able to:

• Calculate measures of central tendency and percentiles on grouped data.
• Construct a frequency polygon.
• Construct a line graph.

The beauty of a coral reef, the warm radiance of sunshine, the sting of sunburn, the X-ray revealing a broken bone, even microwave popcorn—all are brought to us by electromagnetic waves. The list of the various types of electromagnetic waves, ranging from radio transmission waves to nuclear gamma-ray (γ-ray) emissions, is interesting in itself.

Even more intriguing is that all of these different phenomena are manifestations of the same thing—electromagnetic waves (see Figure 15.1). What are electromagnetic waves? How are they created, and how do they travel? How can we understand their widely varying properties? What is the relationship between electric and magnetic effects? These and other questions will be explored.

Photoelectric materials emit electrons when they absorb light of a high-enough frequency.

This online resource introduces the geocentric and heliocentric models. Exoplants, planets and their motions, planetary orbits, the role of gravity and how the solar system was formed are also covered. 

This fascinating video details the journey that a group of friends made in Nevada. Their aim was to illustrate the solar system to scale.