Mechanical and EM Waves PDF

QUARTER 2: PHYSICS 10 Mechanical and EM Waves MECHANICAL WAVES VS ELECTROMAGNETIC WAVES 1. What is a wave? As a wave passes through water, a floating leaf bobs up and down, returning nearly to its original position, like how water molecules rise and fall without signific...

QUARTER 2: PHYSICS 10 Mechanical and EM Waves MECHANICAL WAVES VS ELECTROMAGNETIC WAVES 1. What is a wave? As a wave passes through water, a floating leaf bobs up and down, returning nearly to its original position, like how water molecules rise and fall without significant displacement. This illustrates that waves do not move matter but rather carry energy through a medium. For example, water waves carry energy through water, sound waves through air, and seismic waves within Earth. A wave is a disturbance that transfers energy from one place to another without permanently displacing the medium it travels through. Waves are classified into two main types: mechanical and electromagnetic. 2. Mechanical Waves The substance through which a wave moves is known as the medium. For instance, water serves as the medium for water waves, while the Earth acts as the medium for earthquake waves. Waves that require a medium to travel are known as mechanical waves. Most waves, such as water waves, sound waves, and earthquake waves, fall under this category. At the heart of understanding mechanical waves is recognizing their relationship with matter. When you drop a pebble into a pond, the water’s surface ripples outward. Here, the water particles are not moving outwards with the ripple. Rather, they are moving up and down, transferring the wave’s energy to neighboring particles. The actual matter (water in this case) does not travel a long distance, but the energy does, in the form of a wave. Types of Mechanical Waves Mechanical waves come in different shapes and sizes. There are two main types based on how they move: Transverse waves: In these waves, particles of the medium move perpendicular to the direction of the wave. The crest of a wave is the highest point that it reaches, while the trough of the wave is the lowest point. Light waves and waves on a string are examples of transverse waves.  Theresa G. Dangkulos CLTL-University Science High School QUARTER 2: PHYSICS 10 Mechanical and EM Waves Longitudinal waves: Here, particles of the medium move parallel to the direction of the wave. Compression in a longitudinal wave is a region where the particles are the closest together while rarefaction in a longitudinal wave is a region where the particles are spread out. Sound waves in air are a classic example of longitudinal waves. Difference between Longitudinal and Transverse Longitudinal Transverse The medium moves in the same The medium is moving perpendicular direction of the wave to the direction of wave It acts in one dimension It acts in two dimensions The wave cannot be polarized or aligned The wave can be polarized or aligned This wave can be produced in any This wave can be produced in solid and medium such as gas, liquid or solid liquid’s surface The earthquake P wave is an example Earthquake S wave is an example It is made of rarefactions and It is made of troughs and crests compressions Example of Mechanical Waves Mechanical waves can be further categorized into several types based on their behavior and the media through which they travel. a. Sound Waves Description: Longitudinal waves that travel through air, liquids, and solids. Sound waves are created by vibrating objects and require a medium to propagate. Applications: Used in music, communication, sonar technology, and medical imaging (ultrasound). b. Seismic Waves Description: Waves produced by earthquakes, traveling through the Earth’s crust. They  can be both longitudinal (P-waves) and transverse (S-waves). Applications: Help scientists study the Earth’s interior and locate the epicenter of earthquakes. c. Water Waves Description: Waves that travel along the surface of a body of water. They can be complex, often exhibiting characteristics of both transverse and longitudinal waves. Applications: Important in oceanography, shipping, and the study of coastal erosion. d. Mechanical Waves in Strings Description: Waves that travel along a stretched string or rope. They are typically transverse waves. Applications: Found in musical instruments, such as guitars and violins, where string vibrations create sound. Theresa G. Dangkulos CLTL-University Science High School QUARTER 2: PHYSICS 10 Mechanical and EM Waves 3. Electromagnetic Waves Electromagnetic waves (aka EM waves) were first proposed by James Clerk Maxwell and later confirmed by Heinrich Hertz. These waves are generated by the vibrations between electric and magnetic fields. Unlike the other types of waves, electromagnetic waves do not need a medium to travel— they can move through a vacuum without any problem. In the late 1800s, scientists commonly believed that electromagnetic waves required a medium, which they called the "ether." However, no one was ever able to detect this ether, and we now know that it simply does not exist. The Electromagnetic Spectrum The electromagnetic spectrum is like a giant library of waves, organized by their frequency and wavelength. At one end are the slow, long-wavelength waves, and at the other are fast, high-energy waves. Here is what you will find on this “spectrum”: a. Radio Waves: The giants of the spectrum with long wavelengths, used for communication, from radio broadcasts to Wi-Fi. b. Microwaves: Shorter than radio waves, used in cooking and in satellite communication. c. Infrared: Experienced as heat—think of a warm campfire or the heat from the sun. d. Visible Light: The only part of the spectrum we can see. It’s made up of colors from red to violet, each with its own frequency and wavelength. e. Ultraviolet (UV): Invisible to the human eye but can cause sunburn. UV waves have higher energy than visible light. f. X-rays: High-energy waves that can penetrate most materials, making them useful in  medical imaging. g. Gamma Rays: The most energetic waves, used in certain medical treatments and found in the universe’s most powerful explosions. Theresa G. Dangkulos CLTL-University Science High School QUARTER 2: PHYSICS 10 Mechanical and EM Waves Each type of wave in the spectrum has unique characteristics and uses. The longer the wavelength, the lower the frequency, and the less energy it has; the shorter the wavelength, the higher the frequency, and the more energy it carries. 4. Key Points A wave transfers energy without permanently displacing the medium. Types of Waves: Mechanical Waves - require a medium (e.g., sound, water, seismic waves). Electromagnetic Waves - do not require a medium (e.g., radio waves, visible light, X-rays). Types of Mechanical Waves: Transverse Waves - particle movement is perpendicular to wave direction (e.g., light waves). Longitudinal Waves - particle movement is parallel to wave direction (e.g., sound waves). Electromagnetic Spectrum: Ranges from radio waves to gamma rays, organized by frequency and wavelength. Key Differences: Mechanical waves require a medium; electromagnetic waves do not. Main Reference: Silverio (2011). Exploring Life Through Science, 2nd Edition. Phoenix Publishing House !! Note: Please refer to the last page for your activity !! Theresa G. Dangkulos CLTL-University Science High School QUARTER 2: PHYSICS 10 Mechanical and EM Waves Name: ___________________________ Section: _______________ Check Your Understanding Direction: Print this page (short bondpaper) and answer the following questions to demonstrate your understanding of mechanical and electromagnetic waves. Submit your output on our next face-to-face meeting. Part 1: Short Answer (2 points each) 1. Define a wave. _____________________________________________________________________________________ _____________________________________________________________________________________ 2. What is the primary difference between mechanical waves and electromagnetic waves? _____________________________________________________________________________________ _____________________________________________________________________________________ Part 2: Matching (1 point each) Match the following examples of mechanical waves with their descriptions: Example of Mechanical Wave Description a. Sound Waves 1. Waves produced by earthquakes. b. Seismic Waves 2. Longitudinal waves that require a medium. c. Water Waves 3. Waves that travel along the surface of a body of water. Part 3: Fill in the Blanks (1 point each blank) 1. The part of a transverse wave that is the highest point is called the ___________________, while the lowest point is called the _____________________. 2. The ______________________ spectrum organizes electromagnetic waves by their frequency and wavelength. Part 4: Critical Thinking (5 points each) Discuss one real-world application of mechanical waves and one application of electromagnetic waves. Explain how each application utilizes the properties of the respective wave type. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Theresa G. Dangkulos CLTL-University Science High School