班级 Class

Class 19, Senior 2

题目 Topic

Lesson 5 - Electromagnetic Waves

教学目标和要求 Teaching Objectives

1. What is an electromagnetic wave? How to produce an electromagnetic wave?
2. What is the difference between electromagnetic waves and mechanical waves?
3. Electromagnetic waves are transverse waves. All of the EM waves can be polarized.
4. How to use an equation to represent an electromagnetic wave?

重点难点 Difficulties and Key Points

1. Understand EM waves do not need a medium through which to propagate. While mechanical waves require a physical medium to carry them.
2. Differentiate transverse waves and longitudinal waves.
3. Understand only transverse waves can be polarized. All EM waves can be polarized, thus they are transverse waves.
4. Be able to use a sine or cosine equation to represent a simple sinusoidal EM wave.

上课内容 Course content

1. How to use dual oscillation of electric and magnetic fields to produce an electromagnetic field.
2. Compare the oscillation direction with propagation direction of transverse waves and longitudinal waves.
3. Analyze the polarization experiment of light.
4. Use both graphs and mathematical equations to represent an electromagnetic wave.

作业任务 Assignments

Finish AP Physics 2 Lesson 5 EM Waves Practice Test

存在问题及解决方法 Problems and Solutions

1. Differentiate the different classification methods of waves. Students sometimes may confuse the four different types of wave: mechanical waves, EM waves, transverse waves and longitudinal waves. Teacher should tell them the determination method.
2. Some students may have difficulty to understand the phenomena of polarization. Teacher could use some polarizers to do some experiments with sunlight to show them the difference between unpolarized light and polarized light,