Physics Spec points covered Starter options Practical activity Teacher-led activity CP4a Describing P2.1 Recall that waves transfer 1) Ask students to work In the first part of this activity Set up a ripple tank waves energy and information individually to list all the students use buzzers or lamps with illumination. Place without transferring matter. types of waves they can to send messages in Morse lamp beneath the ripple think of. Ask how the code. The second part of the tank to project the P2.2 Recall and use the terms various suggestions are activity introduces the idea that image onto the ceiling. frequency, wavelength, similar or different, variations in the frequency Make sure the tank is amplitude, period and wave highlighting the ideas to and/or amplitude of a wave can level. velocity as applied to waves. be met in this topic, also be used to transfer particularly the difference information. Use a straight dipper to P2.3 Explain the difference between transverse and illustrate plane waves. between longitudinal and longitudinal waves. Ask students to use Show students how a transverse waves by stopwatches to record microphone connected to an referring to sound, the number of waves 2) Use a 'slinky' spring to oscilloscope can be used to electromagnetic, seismic passing a point in, say, demonstrate longitudinal represent the characteristics of and water waves 10 seconds. Dividing and transverse waves. a sound wave. Challenge them the number counted by Elicit the idea that to come up with a short code 10 will give the although individual coils that uses amplitude and/or frequency in hertz. in the spring move frequency variations to send They could also time backwards and forward or simple messages. Students can how long it takes 10 side to side, the spring as test their codes by making the waves to pass a point. a whole does not move. sounds themselves or by using Dividing this time by 10 a signal generator attached to a Follow up by will give the period of loudspeaker. The students demonstrating waves the waves in seconds. decoding the message can with different amplitudes interpret the sounds, or use the Equipment: Ripple and wavelengths. The oscilloscope trace to see tank and accessories, amplitude of a variations in amplitude or stopwatches, ruler longitudinal wave will be frequency. easier to see if a small Digital Waves video piece of paper is stuck to Equipment: cells or power one of the coils. packs; connecting wires; length of bell wire with stripped ends;
Physics Spec points covered Starter options Practical activity Teacher-led activity CP4a Describing waves P2.1 P2.2 P2.3 Recall that waves transfer energy and information without transferring matter. Recall and use the terms frequency, wavelength, amplitude, period and wave velocity as applied to waves. Explain the difference between longitudinal and transverse waves by referring to sound, electromagnetic, seismic and water waves 1) Ask students to work individually to list all the types of waves they can think of. Ask how the various suggestions are similar or different, highlighting the ideas to be met in this topic, particularly the difference between transverse and longitudinal waves. 2) Use a 'slinky' spring to demonstrate longitudinal and transverse waves. Elicit the idea that although individual coils in the spring move backwards and forward or side to side, the spring as a whole does not move. Follow up by demonstrating waves with different amplitudes and wavelengths. The amplitude of a longitudinal wave will be easier to see if a small piece of paper is stuck to one of the coils. In the first part of this activity students use buzzers or lamps to send messages in Morse code. The second part of the activity introduces the idea that variations in the frequency and/or amplitude of a wave can also be used to transfer information. Show students how a microphone connected to an oscilloscope can be used to represent the characteristics of a sound wave. Challenge them to come up with a short code that uses amplitude and/or frequency variations to send simple messages. Students can test their codes by making the sounds themselves or by using a signal generator attached to a loudspeaker. The students decoding the message can interpret the sounds, or use the oscilloscope trace to see variations in amplitude or frequency. Equipment: cells or power packs; connecting wires; length of bell wire with stripped ends; Set up a ripple tank with illumination. Place lamp beneath the ripple tank to project the image onto the ceiling. Make sure the tank is level. Use a straight dipper to illustrate plane waves. Ask students to use stopwatches to record the number of waves passing a point in, say, 10 seconds. Dividing the number counted by 10 will give the frequency in hertz. They could also time how long it takes 10 waves to pass a point. Dividing this time by 10 will give the period of the waves in seconds. Equipment: Ripple tank and accessories, stopwatches, ruler Digital Waves video