012-03489E5/95© 1988 PASCO scientific $5.00Instruction Manual andExperiment Guide forthe PASCO scientificModel WA-9611, and 9613SONOMETERDETECTORWA-9613DRIVERWA-9613WA-9611SONOMETERKEEP WEIGHTS AS NEAR TO FLOOR AS POSSIBLE IN THE EVENT THE SONOMETER WIRE SHOULD BREAKCAUTION!1.75 kg MAXIMUM LOAD ON LEVER100.5 HzIncludesTeacher's NotesandTypicalExperiment Resultsi012-03489E SonometerTable of ContentsSection PageCopyright, Warranty and Equipment Return......................................................iiIntroduction ......................................................................................................1Equipment ........................................................................................................1Setup and Operation..........................................................................................2Using the Sonometer and the WA-9613 Driver/Detector Coils:Sonometer w/WA-9613, Driver/Detector Coils ........................................... 3Sonometer and Driver/Detector w/PASCO Computer Interface ...................4Power Amplifier w/Series 6500 Computer Interface ....................................4Power Amplifier w/CI-6550 or CI-6565 Computer Interface .......................4Function Generator w/Series 6500 Computer Interface ................................5Function Generator w/CI-6550 or CI-6565 Computer Interface ...................6Replacing Sonometer Strings ............................................................................7Theory of Waves on a Stretched String..............................................................8Experiments:Experiment 1: Resonance Modes of a Stretched String ........................11Experiment 2: Velocity of Wave Propagation ......................................13Suggested Research Topics ..............................................................................16Teacher’s Guide...............................................................................................17Technical Support ....................................................................Inside Back CoveriiSonometer 012-03489ECopyright NoticeThe PASCO scientific Model WA-9611 Sonometermanual is copyrighted and all rights reserved. However,permission is granted to non-profit educational institu-tions for reproduction of any part of this manual provid-ing the reproductions are used only for their laboratoriesand are not sold for profit. Reproduction under any othercircumstances, without the written consent of PASCOscientific, is prohibited.Limited WarrantyPASCO scientific warrants this product to be free fromdefects in materials and workmanship for a period of oneyear from the date of shipment to the customer. PASCOwill repair or replace, at its option, any part of the productwhich is deemed to be defective in material or workman-ship. This warranty does not cover damage to the productcaused by abuse or improper use. Determination ofwhether a product failure is the result of a manufacturingdefect or improper use by the customer shall be madesolely by PASCO scientific. Responsibility for the returnof equipment for warranty repair belongs to the customer.Equipment must be properly packed to prevent damageand shipped postage or freight prepaid. (Damage causedby improper packing of the equipment for return ship-ment will not be covered by the warranty.) Shippingcosts for returning the equipment, after repair, will bepaid by PASCO scientific.Copyright, Warranty and Equipment ReturnPlease—Feel free to duplicate this manualsubject to the copyright restrictions below.CreditsThis manual authored by: Clarence BakkenThis manual edited by: Dave GriffithTeacher’s guide written by: Eric AyarsEquipment ReturnShould the product have to be returned to PASCOscientific for any reason, notify PASCO scientific byletter, phone, or fax BEFORE returning the product.Upon notification, the return authorization andshipping instructions will be promptly issued.When returning equipment for repair, the unitsmust be packed properly. Carriers will not acceptresponsibility for damage caused by improperpacking. To be certain the unit will not bedamaged in shipment, observe the following rules:➀ The packing carton must be strong enough for theitem shipped.➁ Make certain there are at least two inches ofpacking material between any point on theapparatus and the inside walls of the carton.➂ Make certain that the packing material cannot shiftin the box or become compressed, allowing theinstrument come in contact with the packingcarton.Address: PASCO scientific10101 Foothills Blvd.Roseville, CA 95747-7100Phone: (916) 786-3800FAX: (916) 786-3292email: [email protected]: www.pasco.comä NOTE: NO EQUIPMENT WILL BEACCEPTED FOR RETURN WITHOUT ANAUTHORIZATION FROM PASCO.1012-03489E SonometerIntroductionFigure 1 The Sonometer and Suggested AccessoriesDETECTORWA-9613DRIVERWA-9613WA-9611SONOMETERKEEP WEIGHTS AS NEAR TO FLOORAS POSSIBLE IN THE EVENT THESONOMETER WIRE SHOULD BREAKCAUTION!1.75 kg MAXIMUMLOAD ON LEVERBridgeStringTensioningleverSonometer baseIntroductionThe PASCO scientific Model WA-9611 Sonometer is anenhanced version of the classic sonometer. You can per-form the standard, qualitative sonometer experiments,varying the tension, length, and linear density of the stringand observing the effects on the pitch of the plucked string.Also, you can perform quantitative experiments, verifyingthe equations for wave motion on a string by adding theWA-9613 Driver/Detector Coils, a function generator ca-pable of delivering 0.5 A of current, and an oscilloscope (ora computer interface and power amplifier) where,l = wavelengthL = length of stringn = number of antinodesV = velocity of wave propagationT = string tensionm = linear density of stringn = frequency of waveThe driver and detector coil can be placed anywhere alongthe string. The driver coil drives string vibrations at anyfrequency your function generator (or computer-compat-ible power amplifier) will produce. The detector coil allowsyou to view the vibration of the string on your oscilloscopeor computer interface. With a dual trace oscilloscope or acomputer interface, you can examine phase differences be-tween the driving frequency and the string vibrations.EquipmentThe WA-9611 Sonometer comes with the followingequipment (see Figure 1):• Sonometer base with tensioning lever• Two bridges• 10 wires (guitar strings), 2 each of the following di-ameters (linear densities):—