Week 3 - Properties of Waves (PDF)

PROPERTIES OF WAVES Unit 1 – Lesson 1 Day 1- Lesson 1(continued): Properties of waves ► Standards:  ► Identify the properties of waves ► Identify the meaning of amplitude ► Objectives ► Define wavelength ► Identify the m...

PROPERTIES OF WAVES Unit 1 – Lesson 1 Day 1- Lesson 1(continued): Properties of waves ► Standards:  ► Identify the properties of waves ► Identify the meaning of amplitude ► Objectives ► Define wavelength ► Identify the meaning of frequency ► Explain the relationship between energy and amplitude in a wave ► Predict the speed of a wave from a graph with frequency and wavelength  ► Amplitude ► Wavelength ► VOCABULARIES ► Frequency ► Wave speed Starter ► Write the two types of waves in your copybook. Properties of wave - Activity with slinky ► Activity- Use a slinky to see how high the wave moves-how are you able to do that?- Amplitude ► Use a slinky how many waves you can make per given time Frequency ► Use a slinky to see the distance between two crest ► How canwavelength you know how fast your wave is moving? ► Define each words in your own terms Wave speed Think-Pair-Share ► Which of the two picture have high energy-explain ► Which of the two pictures have high energy-explain  Energy and Amplitude in a wave ► The amplitude of a wave is dependent on energy ► When comparing waves of the same frequency in the same medium The energy of a wave is proportional to the amplitude of the wave squared, ► A wave with a larger amplitude carries more energy than a wave with small amplitude does.  Check your understanding ► Which of the following wave has high amplitude and which one has low amplitude (explain your answer)  Properties of wave- Amplitude , wavelength , frequency and wave speed Wave are described by their properties ► Amplitude: is the measure of how far a particle in the medium moves away from its normal position. ► Amplitude is half of the difference between the crest and the trough ► Wavelength: the distance from any point on the wave to an identical point on the next wave pulse (crest to crest, or trough trough). ► Wavelength measures the length of one cycle, or repetition of a wave.  Properties of wave- Frequency and wave speed ► Frequency: is the number of wave produced in a set amount of time ► Frequency is usually expressed in hertz (Hz) ► For waves one hertz equals one wave per second (1 HZ=1/s) ► Wave speed: is the rate at which a wave travels. ► Wave speed can be calculated by multiplying wavelength and frequency Speed of Waves Wave speed = frequency x wavelength Symbols V = f x λ units = m/s = Hz x m Wave speed  Check your understanding: Group work Group 1- Define frequency, wavelength, amplitude, and wave speed Group 2- Describe the relationship between frequency and wavelength Group 3- Explain the relationship between amplitude and energy Group 4- Write the formula for calculating the speed of a wave and units of speed of wave, wavelength and frequency. Engineer it – Challenge question ► An engineer has been asked to give advice about a wave pool at a local water park. The wave pool is generating waves that move to fast for the safety of park guests. Explain why the engineer suggested reducing the frequency of the wave generator. ► Hint- relate your understanding of the relationship among energy, frequency, and amplitude to this engineering problem. Objectives: ❖ Write the formula for wave speed ❖ Calculate wave speed Day 2 ❖ Derive a formula to calculate wavelength or frequency from speed formula Starter: ► Write the formula for wave speed in your copybook. Previous Knowledge: Wave speed = frequency x wavelength V = f x λ = m/s = Hz x m I Do: Wave speed Calculations. Determine the wave speed of a wave that has a wavelength of 5m and a frequency of 4 Hz. Given: f = 4 Hz, Answer: Step 1: λ = 5 m. Write the Formula speed wave (V) = f x λ V= ? Step2: Substitute by numbers =4x5 Step 3: Write the answer = 20 (m/s) Step 4: Write the unit We Do: Wave speed Calculations. Determine the wave speed of a wave that has a wavelength of 2m and a frequency of 9 Hz. Given: f = 9 Hz, Answer: Step 1: λ = 2 m. Write the Formula speed wave (V) = f x λ V= ? Step2: Substitute by numbers =9x2 Step 3: Write the answer = 18 (m/s) Step 4: Write the unit You Do: Wave speed Calculations. A wave traveled with speed of 15 m/s that has a wavelength of 5 m, determine the frequency. Given: Step 1: f = ? Hz, Write the Formula λ = 5 m. V= 15 m/s Step2: Substitute by numbers Step 3: Write the answer (Hz) Step 4: Write the unit  Extra Activity-Quizizz wave speed calculation - Quizizz: - https://quizizz.com/join?gc=696858 - Jeopardy: - https://jeopardylabs.com/play/types-of-waves-18 Day 3 – Diagnostic Test Day 4 - Objectives ► List types of mechanical waves ► Explain how waves move energy ► Compare between longitudinal and transvers waves Starter: What is the difference between the waves in the picture? Numbered heads together Book Exercises, Pages: 7, 11, 12, 20-21 Instructions: 1) Teacher will divide you into groups of 4 or 5 students. 2) Each student in each group will have a certain number. 3) First, each student will answer a question 30 sec - 1 min independently. 4) Students in groups will then discuss and share their answers in 1 min. 5) Teacher will call a number to get the answer from each group, student of the called number from each group will share it. 6) The teacher will listen to all answers and then share the correct answer.