Topicm563c54340858243b_1528449000663_0Topic

The use of the relationship between the period and the frequency, the speed and wave length in calculations

Levelm563c54340858243b_1528449084556_0Level

Second

Core curriculumm563c54340858243b_1528449076687_0Core curriculum

VIII. Vibrating motion and waves. The student:

5) uses the concepts of the amplitude, the period, the frequency and the wavelength to describe waves and applies the relationship between these quantities and their units in calculations.

Timingm563c54340858243b_1528449068082_0Timing

45 minutes

General learning objectivesm563c54340858243b_1528449523725_0General learning objectives

Developing problem solving skills.

Key competencesm563c54340858243b_1528449552113_0Key competences

1. Developing the ability to use the concept of amplitude, frequency and wavelength.

2. Using knowledge to do typical tasks.

3. Using knowledge to do problem tasks.

Operational (detailed) goalsm563c54340858243b_1528450430307_0Operational (detailed) goals

The student:

- uses the quantities describing the vibrating and wave motion,

- does problem tasks, typical and new ones, in cooperation with the group.

Methodsm563c54340858243b_1528449534267_0Methods

1. Independent learning by solving problems.

2. Formulating problems and ideas for solving them.

Forms of workm563c54340858243b_1528449514617_0Forms of work

1. Individual work on doing tasks.

2. Collaboration in the group during solving problem tasks.

Lesson stages

Introductionm563c54340858243b_1528450127855_0Introduction

Please prepare the answers to the following questions:

1. What is the vibrating motion?
2. Define the basic quantities describing the vibrating motion.
3. What is the mathematical pendulummathematical pendulummathematical pendulum?
4. What is the natural frequency?
5. Present on the graph the dependence between the displacement on time in the undamped harmonic motion and in the suppressed one.
6. Describe the mechanical energy changes which occur during the motion of the harmonic oscillator.
7. What is the mechanical wave and what is the propagation of a mechanical wave?
8. Define the basic quantities describing the propagating wave.
9. Classify the waves according to the direction of wave propagationwave propagationwave propagation and the direction of vibrations.
10. What is the sound?
11. List and describe the properties of thesound.
12. What is echo and reverb?
13. What are ultrasoundsultrasoundsultrasounds and infrasounds?

Procedurem563c54340858243b_1528446435040_0Procedure

Solve the online test that revising the knowledge about vibrations and harmonic waves.

Lesson summarym563c54340858243b_1528450119332_0Lesson summary

The wavelength (λ) is the distance between consecutive repetitions of the waveform. In other words, it is the smallest distance, measured parallel to the direction of the wave propagation, between the points which are in the same vibration phase.

The wavelength is most is most easily determined by giving the distance between two consecutive wave crests or between its consecutive troughs.

For a wave spreading at the velocity v its length can be expressed:m563c54340858243b_1527752256679_0The wavelength (λ) is the distance between consecutive repetitions of the waveform. In other words, it is the smallest distance, measured parallel to the direction of the wave propagation, between the points which are in the same vibration phase.

The wavelength is most is most easily determined by giving the distance between two consecutive wave crests or between its consecutive troughs.

For a wave spreading at the velocity v its length can be expressed:

where: 
T - vibration periodvibration periodvibration period.

The wave moving at speed v during one period will cover the distance equal to its length.

The wave period is the time when any wave point will make one full vibration.

The frequency (f) of the wave is the quantity informing us about the rate of repetition of the vibrations of a given point of the medium in which the wave propagates. Because the period is the duration of one full cycle of vibrations, the frequency (informing us about the number of cycles per unit of time) must be equal to its inverse:m563c54340858243b_1527752263647_0The frequency (f) of the wave is the quantity informing us about the rate of repetition of the vibrations of a given point of the medium in which the wave propagates. Because the period is the duration of one full cycle of vibrations, the frequency (informing us about the number of cycles per unit of time) must be equal to its inverse:

By inserting the last expression into the wavelength formula we get:

Selected words and expressions used in the lesson plan

frequency of vibrationsfrequency of vibrationsfrequency of vibrations

harmonic oscillationsharmonic oscillationsharmonic oscillations

harmonic waveharmonic waveharmonic wave

infrasoundinfrasoundinfrasound

mathematical pendulummathematical pendulummathematical pendulum

ultrasoundsultrasoundsultrasounds

vibration periodvibration periodvibration period

wave crestwave crestwave crest

wave propagationwave propagationwave propagation

wave troughwave troughwave trough