Mechanical Waves: Understanding Transverse, Longitudinal, and Surface Waves, Exams of Particle Physics

Download Mechanical Waves: Understanding Transverse, Longitudinal, and Surface Waves and more Exams Particle Physics in PDF only on Docsity! 17.2 - Waves Mechanical Waves A disturbance in matter that carries energy from one place to another. Medium The material through which a wave travels. • Medium can be any three states of matter: solid, liquid or gas Waves Transverse Waves Examples: 1. Shaking the end of a rope up and down 2. Shaking one end of the blanket up and down 3. Wave in the ball park Transverse Waves Longitudinal Waves A wave in which the vibration of the medium is parallel to the direction to the direction the waves travel. Compression An area where the particles in a medium are spaced close together. Rarefaction An area where the particles in a medium are spread out. Longitudinal Waves Longitudinal Waves Examples: 1. Waves produced by earthquakes 2. Sound Waves 3. Ultrasound Longitudinal Waves Surface Waves Examples: 1. Ocean Waves 2. A fishing bobber floating Surface Waves Period Motion Any motion that repeats at regular time intervals Frequency Number of complete cycles in a given time  Frequency is measured in Hertz (Hz) Properties of Mechanical Waves Wavelength The distance between a point on one wave and the same point on the next cycle of the wave. Properties of Mechanical Waves 5 10 15 20 25 30 35 40 25m - 5m = 20m (m) • Measure from any identical two successive points What is the wavelength Key point Increasing the frequency of a wave decreases its wavelength. Properties of Mechanical Waves Key Point Frequency and wavelength are inversely proportional meaning when one goes up, the other goes down. Wave Speed Example #1 A wave on a rope has a wavelength of 1.8 meters and a frequency of 2.3 Hz. What is the speed of the wave? Wave Speed Examples S = W x F S = 1.8 m x 2.3 Hz S = 4.14 m/s Example #2 A motorboat is tied to a dock with its motor running. The spinning propeller makes a surface wave with the water with a frequency of 4 Hz and a wavelength of 0.1 meters. What is the speed of the wave? Wave Speed Examples S = W x F S = 0.1 m x 4 Hz S = 0.40 m/s Example #3 What is the wavelength of an earthquake wave if it has a speed of 5,000 m/s and a frequency of 10 Hz? Wave Speed Examples W = S / F W = 5,000 m/s / 10 Hz W = 500 m Label the following in the wave below:  Rest Position  Wavelength  Compression  Rarefaction  Amplitude Properties of Mechanical Waves 17.2 Assessment Questions 1. What are the three types of mechanical waves?  Transverse  Longitudinal  Surface 2. How are mechanical waves produced? A disturbance in matter that carries energy from one place to another 17.2 Assessment Questions 3. How are transverse and longitudinal waves alike? They both carry energy 4. How are transverse and longitudinal waves different? Transverse carry energy at right angles Longitudinal carry energy parallel