0635 Name Eiyad KhairyGrade 8N Essays - Waves, Acoustics

0635 Name Eiyad KhairyGrade 8N Essays - Waves, Acoustics 0-635 Name: Grade 8(N) MYP Science Title: Sound Key concept: Relationships Related concepts: Relationships / Models / interaction Global contexts: Identities and relationships / Roles and role models Topic: The sound wave Statement of inquiry: Models can represent the structural and functional relationship between sound and energy. Inquiry questions: Factual: What is the sound? Conceptual: How do sound travel through mediums? Debatable: What are the applications based on echo? MYP Assessment Criteria B- Inquiring and designing C- Processing and evaluating Writing a lab report about The sound wave Due date is before Tuesday 17/3/2015 Theoretical background Waves transmit energy without transmitting matter. This means that waves can move energy (or information) from one place to another without moving any substance (stuff) from one place to another. The amount of energy which a wave depends on its amplitude. Longitudinal waves move through substance backwards and forwards. After the wave has gone, the substance is back where it started but energy has been carried by the wave from its origin (where it begins) to its destination (where it finishes). The sound wave is a longitudinal wave. It cant travel through a vacuum (nothing), when a longitudinal wave moves through a material, the particles of the material move backwards and forwards along the direction in which the wave is travelling. Below is a picture of a longitudinal wave travelling along a slinky. Rarefaction is the name given to the region where the slinky is pulled apart. Compression is the name given to the region where the slinky is pushed together. The wavelength can be measured as the distance between the centers of two compressions. Wavelength is given the symbol l (Greek lambda), and is measured in meters because it is a distance. Denoted by . Frequency is defined as "the number of complete cycles (complete waves or vibrations) in one second". Hertz is the unit of frequency (symbol Hz). Denoted by . The period of a wave is defined as "the time taken for one complete cycle or vibration". Denoted by T. The wave equation links between frequency and wavelength: Speed = frequency x wavelength v=f f= 1T= ntWhere: v is speed measuren in [M/s] f is frequency measured in [Hz]T is periodic time time needed to complete one cycle measured in [s] N is the number of vibrations T is total time of vibrations measured in [s] Aims: In this investigation you will be able to: Use slinky to calculate the frequency of a wave. Materials: Slinky Stopwatch Meter stick Task: Your task is to write a lab report about longitudinal waves. Procedure Stretch the slinky between two group members without making it too tight. Make sure the slinky is lying on the floor (as shown in figure 1 below) Create a longitudinal wave pulse by pushing the slinky forward parallel to it. The slinky should still be in a straight line and the wave pulse (squished up part) should travel to the other end of the slinky. Measure the distance that the wave travels between people (the length of the slinky) in meters and record this in table 1. The third person should time the wave through this distance, from one person to another. Enter this time into table 1. You will record the time it takes the longitudinal wave to travel from one person to another for a total of three separate times. These times will not be exactly the same, but should be close to each other. The fourth person should count the number of pulses pass through the slinky for each time. Average these times and enter the average in table 1. To average the time add them up and divide by their number. average time= time1+time2+time33Calculate the speed of this longitudinal wave using the wave equation: speedms=distance traveled (m)time (s)Record the speed of this longitudinal wave you calculated into table 1 in meters per second. Show your work and calculation in analysis part. Communicate scientific information effectively using scientific language correctly. Present all the information appropriately using symbolic and/or visual representation accurately according to the chosen application. Figure 1 Part 1: Introduction Problem statement: How does the amount of vibration affect the frequency? Hypothesis: If the amount of vibration increases then the frequency will increase. Explaining the hypothesis: The frequency will increase because it depends on the amount of vibration speed. Dependent Variable: Frequency Independent Variable: The amount of vibration Controlled variables: Time: (1 min) Equipment: Slinky Stopwatch Meter stick Procedure: I stretched the slinky between