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.

This video explores how to find the mean from data in a table.

This video explores the histogram: which is one of the ways in which to present data.

Video 1: How to create a line graph based on data
Video 2: Examples of different line graphs
Video 3: Further examples of line graphs

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.

An image that illustrates light reflecting off a plain mirror.

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

This video explains how pie charts can be used to display data in a more 'user-friendly' way.