A Detailed Lesson Plan on the Nature and Characteristics of Waves
I.
Objectives:
At the end of the activity most of the students should be able to; (a) Explain how waves are produce. (b) Describe and explain wave motion as illustrated by vibrations in ropes, and by water in the sea. (c) Distinguish between transverse and longitudinal waves, and give suitable examples of each. II. Subject Matter A. Topic: Nature and Characteristics of Waves B. Learning Materials: (a) 1 rope (b) Flash animations (c) movie clips (d) PowerPoint Slides C. References: Grade 7 TeachingGuide (Dep.Ed), Phet.Colorado.com/ PhetSim D. Science Process Skills Explaining and constructing E. Value Integration Showing interest during the teaching-learning process. F. Teaching Strategy Discussion, Collaborative Activity and PowerPoint Presentation III. Developmental Task
Teacher’s Activity Student’s Activity Good Morning Class. We will have an Students: Good Morning Sir. activity for today. Class have ever seen or heard about tsunami wave?
Students: Yes sir!
This time I will show you a video clip about a tsunami that hit Japan in 2011. Have you heard that in the news? Who of you watch news here? Okay.....please watch this (The teacher will play the clip) So class what are your thoughts about what you have seen in the video? That’s right that’s why when you go to the beach you must be vigilant. We cannot tell what time a tsunami will happen. Right? According to what you have heard in the news if so happened that you really watch news.....what was the cause of this tsunami?
Jeiril: It was terrifying and destructive sir. I’m sure many houses and buildings were destroyed.
Dharlene: Sir because of earthquake in the ocean that’s why that happened sir.
Yes..of course! Tsunami is caused by an earthquake in the ocean or what geologists called under water earthquake. Now, I will ask you.....what is in your mind when say wave...just like what you have seen in the video? That right! What a brilliant idea Perly.
Perly : Wave are like one of those in the ocean that we can see when we go out for a picnic at the beach sir.
What else? That is absolutely commendable idea Mea. Very good.
Mea: A tsunami wave sir.....I remember when I watched news about what happened in Phuket Thailand. Many people died in that terrifying calamity.
But what we know about wave now is just a part of what we are about to know in this lesson. In this lesson we will learn what is a wave, how it is formed or produce, or what causes its existence its nature and characteristics. Waves that we can see in the ocean are good example of a wave. However, our idea about wave must not be confined only in that example. Later, as we go along our lesson, we will encounter different types and sources of waves. Like sound waves, light waves (electromagnetic wave) etc. So waves are everywhere. Do you agree on that class? Later we will know where we could possibly found some more waves. Before that I will show you how wave is formed, what causes it and it affects as all.
Students: Yes sir.
.
(The teacher will show a picture of a water ripple to the class) Now class I will show a picture of how the water in turns into a ripples or waves. So what do you think causes the water to ripple or form into waves?
Jeiril: Because of the wind sir.
Correct…very good! So wind causes a disturbance in the water as it blows at the sea. But aside from that how do you think can be a wave at the sea formed?
Perly: By an earthquake sir. Based on the video that we have watch a while ago waves can be formed because of tsunami caused by an earthquake.
Very good! So. Based on your experience in water at the sea...how do you think waves are formed or created?
Dharlene: Waves are formed because of disturbances. Like the wind that blows the water at the sea it provides force that create waves.
Yes Dharlene is right. Very good! In other words what do we mean by wave?
Mea: A wave is a disturbance sir.
By the way..let us first understand the word medium. What do we mean by the word medium ? Any idea? Yes, Mea?
That’s is very good example Mea,thank you.
In the case of the water at the sea, what do you think is the medium?
A medium is a substance or material that carries the wave. You have perhaps heard of the phrase news media. The news media refers to the various institutions (newspaper offices, television stations, radio stations, etc.) within our society that carry the news from one location to another. Who can give me an example of a news
Mea: In my own understanding of the word medium, it is like a thing that enables another thing to go from one place to another place. Like for example when we go to the city we have to ride on a bus or taxi in order for us to reach our destination. We may consider a vehicle like a bus as a medium which helps us reach our destination.
Perly: At the sea, water carries the wave and we can see that the wave that the water carries moves from one place to another. Therefore we can say that the water at the sea is a medium which carries the wave on it.
media? Perly: TV Patrol sir. What else? Correct!
Mea: 24 Oras sir.
The news moves through the media. The media doesn't make the news and the media isn't the same as the news. The news media is merely the thing that carries the news from its source to various locations. In a similar manner, a wave medium is the substance that carries a wave (or disturbance) from one location to another. I’m gonna show you right now a clip that describes how ocean waves are formed similar to our activity a while ago. (The teacher will show a clip on ocean wave) What have observed about the boat at the sea after encountering those waves along its destination?
Perly: The boat is battling against the sea wave.
Yes, that’s very obvious Perly.Thank you By what can you say about the boat as it continues to overcome the waves that bumps it. Did the boat move together with the wave? Yes Dharlene?
Dharlene:No sir, as the wave strikes against the boat, the boat is just there and it doesn’t move.
Very good. Thank you Dharlene In this example we can generally say that wave does not carry or transport matter but it only carries energy. Right Class? Students: Yes Sir
(The teacher will show a video clip) What have observed about the duck in the video as the wave pass through it?Mea?
Mea: The duck moves up and down as the waves pass through it.
What else? Yes..Jeiril.
Jeiril: Even if the duck moves up and down as the wave pass through it, it did not travel along with the wave but it returns to its original position as the the waves rest or stop
So..according to you as the wave propagates towards the duck, the duck remains in its position and never travel along the wave..right? So what can you say based on that observation?
Jeiril:Based on my observation with the wave and the duck in the video, I can say that waves carry energy but not any matter because the duck remain in its position as the wave travels. It only moves up and down but did not travel along the wave.
So generally speaking, wave carries energy.....energy that might be in the form of light or sound etc...transmitted through a medium and it will never carry matter. Students: Yes Sir Do you agree on that? The wave medium is not the wave and it doesn't make the wave; it merely carries or transports the wave from its source to other locations. In the case of a water wave in the ocean, the medium through which the wave travels is the ocean water. In the case of a sound wave moving from the church choir to the pews, the medium through which the sound wave travels is the air in the room. And in the case of the stadium wave, the medium through which the stadium wave travels is the fans that are in the stadium. There are two types of waves, Transverse wave and Longitudinal wave. (The teacher will call two students
volunteer to do the activity in front of the class. The teacher then get the rope and do the instruction) Okay class here’s what we are going to do. First, Perly will hold the rope from one end and Mea will hold it from the other end. (Then the teacher take the attention of his student Perly) Now, what I want you to do is to make a wave in this rope with a slight speed. ....then with a medium speed ....then with a faster speed. Now, what have you observe about the rope as Perly moves it up and down? Jeiril: It forms like a wave sir. Yes Jeiril please? That’s right !Very Good ! The rest please observe and prepare for my questions later. (Jeiril and Dharlene perform the activity ) That is right. In our activity this vibration on the rope is created because of ENERGY. Based on the activity with the rope where do you think that energy come from? Or who do you think is the source of that energy? Jeiril? Correct. In our activity with the rope we may consider Perly as an energy source and the
Jeiril: Since Perly is the one who is holding the rope and vibrates it therefore Perly is the source of the Energy which enables the rope to vibrate.
rope as the medium where the energy passes through. Do you agree on that class? Mea: It vibrates or moves up and down. Now, as Perly applies her energy to move the rope....what happened to the rope then? Of course! Theoretically speaking, as Perly applies a force to move the rope she only transfers her energy on the rope and that energy is in the form of wave. Actually it really forms like a wave am I right?
Now, will find out what is a transverse wave. (The teacher calls for Mea and Perly to repeat the activity again with the rope) Please observe the wave again. Look at the position and direction of the wave produce. As Perly vibrates the rope, what have you observe with the direction of her hand and the direction of the travel of the wave?
So, based on that observation how could you define transverse wave?
That’s right! Very good.
Remember that this particle may also refer to any matter that is carried by the wave or
Dharlene: I have observe that Perly’s hand moves up and down to create a vibration on the rope and this vibration perpendicular to the direction of the travel of the wave. Dharlene:A transverse wave is a wave in which particles of the medium move in a direction perpendicular to the direction that the wave moves.
in this case the particle is the rope itself. Another category of wave is called “Longitudinal Wave” The best example of this is the sound wave. For us to better understand what is meant longitudinal wave....it is better that we use slinky coil. Unfortunately it is not available but I’m going to show a short illustration of how longitudinal wave is formed and how it transport energy. Please watch this.(The teacher will play a an animation) So based on your observation what is the direction of the vibration? Yes Jeiril.
How could you describe longitudinal wave then? Mea?
Jeiril: As I watch the animation I have notice that the wave moves along the direction of the wave. Mea: Based on my observation the waves or vibration and the direction of its travel is the same. Therefore as what Jeiril said longitudinal wave is a type of wave that is characterized by particle motion being parallel to wave motion.
Longitudinal waves are always characterized by particle motion being parallel to wave motion. Right! Very good!
Perhaps it is a little bit confusing to describe longitudinal wave...so to better understand it I will show you again an illustration about Longitudinal wave as well as transverse wave for you to better see how they differ from each other. (the teacher presents a PowerPoint slides)
Now class, can you describe now how longitudinal wave formed? Can you now differentiate transverse wave
Mea: A transverse wave is a wave in
from longitudinal wave? Yes Mea?
which particles of the medium move in a direction perpendicular to the direction that the wave moves while Longitudinal wave is a type of wave in which the particles of the medium moves parallel to the direction of the wave.
VI. Assessment Test I. Identification 1.The repeating and periodic disturbance that moves through a medium from one location to another is referred to as a__________? 2.It is a substance or material that carries the wave. 3. If wave does not transport matter what does it transport from one place to another? 4.It is a wave in which particles of the medium move in a direction perpendicular to the direction that the wave moves. 5.It is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves. 6.A___________ wave traveling through air is a classic example of a longitudinal wave. 7. What is an example of a transverse wave? 9-10 Differentiate transverse wave from longitudinal wave.
VII. Assignment Please research and define the following terms for our next lesson tomorrow. 1. Speed 2. Frequency 3. Wavelength 4. Period 5. amplitude
