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Physics of Sound. Investigation 1: Dropping In Part 3 Sound and Vibrations. Objectives. I can identify a sound source . I can identify a sound receiver . I can describe , orally and in writing, what happens to vibrations when volume changes . Sound and Vibrations.
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Physics of Sound Investigation 1: Dropping In Part 3 Sound and Vibrations
Objectives • I can identify a sound source. • I can identify a sound receiver. • I can describe, orally and in writing, what happens to vibrations when volume changes.
Sound and Vibrations • We will be exploring sounds made by two different objects. Watch how to use each object appropriately. • Long gong • Tuning fork • Treat the instruments with care. • If you hit them too hard, they may break.
Tuning Fork and Long Gong • You will get time to get to know the instruments, then you will use them for an investigation. • 5 minutes to explore • Repackage instrument • Switch with another group • GETTERs get materials. • STARTERs watch the clock and make sure everyone gets a turn.
Share Observations • Return all materials to the bags. • Think-Pair-Share • What did you hear? • What were the properties of the sounds you heard? • What did you see when the two instruments made sounds?
Door Fiddle • Guess what the teacher is making. • What do you see? • What do you hear? • How does the string feel when it is making its sound?
Tone Generator • Watch the beans! • What do you see? • What do you hear? • How does the speaker feel when it is making its sound?
Tone Generator • The quick back-and-forth movement of the string and speaker cone that you observed is called a VIBRATION. • Sometimes vibrations are so fast that they are easier to feel than they are to see. • Some vibrations feel like a tickle or a buzz. • Where have you felt vibrations? What did you hear when you felt the vibration?
Investigate • We will use the long gongs and tuning forks to do detailed investigations. • This time you should look for vibrations when the turning fork and the long gong are making their sounds.
Student Sheets • Open your yellow Physics of Sound packet to “The Tuning Fork” and “The Long Gong.” • Look at the headings. You will be expected to record information on these sheets while you investigate. • READ THE INSTRUCTIONS CAREFULLY. • Underline key words!
MiniActivities • STARTERs read the instructions aloud to the group. • After that, GETTERs get the materials. • When you are done with one activity, have a teacher check your sheet. They will let you know if you can move on to the next activity.
Think About • What causes sound? • What is vibrating when you hear the sounds? • T-P-S • Return materials.
The Source • Close your eyes. Be VERY quiet. Listen carefully to the sounds all around you for the next minute or so. • Raise your hand and identify a sound you heard. • Sound comes from a source. A sound source is where a vibration starts. Usually a sound source is a vibrating object, like a wire arch, a tuning fork, or a speaker cone.
The Receiver • In order for a sound source to be heard, is must be detected (found) by a sound receiver. A sound receiver is something that responds to vibrations generated by a sound source. • Our ears are our sound receivers. • What other sound receivers can you think of?
Volume • Demonstration: work with volume dial on tone generator, keeping the pitch the same. • What is the sound source? • What is the sound receiver? • How is the sound changing? • What happens to the vibrations when the sound is louder or softer?
Volume • Volume describes how loud a sound is. • STRONG vibrations make LOUD sounds. • Weak vibrations make soft sounds. • Volume is measured in decibels, named for Alexander Graham Bell, the inventor of the telephone.
Volume • Explore volume with the door fiddle, tone generator, tuning fork, and long gong. • Identify the sound sourcesand receivers. • How intense (strong or weak) is the vibration while the sound is being made?
Objectives • I can identify a sound source. • I can identify a sound receiver. • I can describe, orally and in writing, what happens to vibrations when volume changes.
Review/Reflect • What do vibrationshave to do with sound? • What are some examples of sound sources? • What are some examples of sound receivers? • What happens to the vibrations when the volume changes?
