Results

An interactive lesson discussing congruent triangles.

Outcomes

In this course you will learn about:

1. Conditions for congruency.
2. Proving congruent triangles.

The Earth behaves like a giant bar magnet and as such there is a magnetic field present around it. The Earth’s magnetic field is thought to be caused by flowing liquid metals in the outer core of the planet which causes electric currents and a magnetic field.

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.

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.

Outcomes

By the end of this course you will:

• Be able to define the 'reflection of light'
• Understand the difference between reflected and incident rays
• Be familiar with the two types of reflection viz.: regular and irregular reflection
• Have an understanding of the laws of reflection