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.

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.

In this unit you will: 

• Understand that temperature is a measure of average kinetic energy.
• Learn about the various temperature scales that are commonly used in science.
• Learn to read temperature scales.
• Differentiate between various thermometers (alcohol or mercury-based).
• Understand that physical properties change when there is a change of temperature.

Visualising, adding and breaking down vectors in 2 dimensions.

In this unit you will learn what a force is and find out about different types of forces. This will allow you to identify forces at work in your everyday life and understand the effects of forces.