Smithsnian Latin Center Meet the Science Expert DESCUBRA! CREATE-IT POCKET SCIENCE HANDOUTS DESIGN AND BUILD WIND INSTRUMENTS 1. Overview: Wrking with different sized straws and ther materials (see the list in the Preparatin sectin belw), children will learn t design and cnstruct instruments called membranphnes. These instruments prduce sund thrugh the vibratin f a membrane tautly stretched ver a cavity. Drums are membranphnes, s are kazs. The membranphne that the children will cnstruct in this exercise will lk like the illustratin in Figure 1. Once they have built a basic membranphne, the children will mdify it t prduce different frequency sunds and t amplify the sunds it makes. As part f this experience, children will gain a basic understanding f hw sund is made and hw it travels. They als will learn sme elementary prperties f sund, such as hw lw sunds and high sunds are prduced and hw sund must travel thrugh a medium (air r water) in rder t be heard. Age level: 8-10 years Time frame: Preparatin: 35 minutes Activity itself: 45 minutes Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin.
Smithsnian Latin Center 2. Backgrund: Sund is vibratin is a seemingly simple statement that describes an extremely cmplex idea. All that yung peple need t knw here, hwever, is that if they shake (vibrate) smething fast enugh, they will be able t make a sund. Fr example, if yu vibrate smething 60 times per secnd, yu will make a sund that has the same tne as the hum f yur refrigeratr. And, if yu vibrate smething 256 times per secnd, yu will make a tne just like a pian s middle C. The faster an bject vibrates, the higher its pitch; the slwer it vibrates, the lwer its pitch. Lnger instruments make lwer sunds than shrter instruments. By blwing air int the elbw straw, the air pressure will mve the rubber membrane up, but because it is elastic, it will snap back. The rate at which the membrane ges up and dwn depends n the length f the straw 3. Preparatin: Materials fr each child: Fig. 1 fur 3/8-inch bubble tea straws tw regular-size elbw jint straws ne latex glve tw 5-inch lng, 3/8-inch utside diameter clear sft plastic tubing (plumbing tubing) tw sheets f cmputer paper Additinal materials: ne rll f masking tape per fur children ne hle punch per eight children ne scissrs per child Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 2
Smithsnian Latin Center 4. Making and Ding: Making a membranphne Cut the elbw straw crsswise in half; discard the prtin f the straw withut the elbw jint. Have the child cut ut a finger frm the latex glve and then cut a small pening at the finger tip, just large enugh fr the elbw straw t fit thrugh. Insert abut ne-half inch f the elbw straw (yu may use either tip f the straw fr this) int the hle and tape the straw securely nt the latex finger, as shwn in Figure.2. Fig. 2 Next, insert rughly ne-half inch f the bubble tea straw int the remaining pen end f the latex finger and tape the finger frm the utside, as shwn in Fig. 3. Fig. 3 Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 3
Smithsnian Latin Center The next step requires tw sets f hands. Pre-cut abut tw inches f masking tape. Have the child bend the elbw jint and begin blwing int the straw, cntinue t bend the elbw until a pure tne is heard. As sn as the tne is heard, tape the narrw straw t the wider ne (using the pre-cut masking tape), as shwn in Fig. 4. (If yu lse the tne, just und the tape and repeat the prcess until yu find the tne again.) The child nw has cnstructed a ne-nte membranphne, and nw the real fun can begin additinal ntes can be added t the instrument and its sund can be amplified. Making a flute Fig. 4 Have the child cut a large straw lengthwise thrugh the middle with the scissrs (Fig. 5). Then punch tw r mre hles, abut ne-inch apart, anywhere alng the sliced straw s length. Finally, attach the sliced straw t the existing large straw, slipping it ver its end and taping the slit shut s n air can escape. By cvering the hles with his r her fingers, the child can change the sund. The shrter the path f the air flw, the quicker the vibratin and the higher the pitch. Cvering the hles alng the length f the straw shrtens r lengthens the straw, which creates different pitches just like playing a flute. Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 4
Smithsnian Latin Center Fig. 5 Making a trmbne The pitch can als be lwered by lengthening the cylinder. T d this, slice abut ¾ f an inch frm the straw and slip a new straw int the musical instrument, as shwn in Fig. 6. Straws have a blunt end and pinted ne. When jining ne straw t anther, insert the pinted end f the secnd straw int the blunt, slit end f the first straw. Then tape the junctin s that n air escapes. Fig. 6 The instrument can als be lengthened r shrtened by cutting a large straw dwn the middle and slipping it ver the vibrating straw, then putting tape alng the length f the straw and sliding the large straw back and frth. Make sure the assembly is lse enugh t allw the larger straw t easily mve in an ut just like a trmbne. Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 5
Smithsnian Latin Center Making a trumpet Nw let s make the instrument luder. First let s make a cne called a bell ut f cmputer paper and attach it t the end f the instrument. Mst wind instruments have bells think f trumpets, saxphnes, and clarinets. Any time yu jin straws r bells make sure that yu tape the jints well. Air leaks will affect the sund f the instrument. Yu can als attach a 3/8-inch piece f plastic tubing between the bell and the straw t further amplify and redirect sund. (See Figure 7.) Fig. 7 Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 6
Smithsnian Latin Center Lessns learned: By learning t build musical instruments, the children will gain an insight n the science f sund. They will cme t understand the meaning f tne and pitch, and their relatinship t the size, length, and shape f an instrument. Each ne f these experiments will pse sme cnstructin challenges and that is a gd thing. Mst cntemprary learning thery agrees that deep understanding happens best when a student wrks thrugh the struggles that lead t success. Humans are wired (prgrammed) t learn frm mistakes. Fr example, if a student were t get verly ambitius and build an verly lng instrument that is t lng, this will require that he r she blw harder. Mrever, even thugh this lnger instrument will have a lwer pitch, blwing harder called ver-blwing will make the sund mve up an ctave. This is precisely hw trumpet players get mre than ne ctave frm an instrument that has few valves. This activity will enable the children t emerge with a sense f success tempered by a bit f struggle frm vercming bstacles. Wh knws? Sme f these children may be inspired t find ut mre abut sund and music. Sme may even want t pursue a musical career playing wind instruments. Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 7
Smithsnian Latin Center My Ntes and Observatins Descubra! Meet the Science Expert is made pssible, in part, thrugh prgram supprt prvided by NBCUniversal Telemund Enterprises. T learn mre abut ur spnsr s educatinal resurces, visit http://www.telemund.cm/el-pder-en-ti/tu-educacin. 8