3B SCIENTIFIC PHYSICS U8431776 Fiche d'instruction - Page 4

Parcourez en ligne ou téléchargez le pdf Fiche d'instruction pour {nom_de_la_catégorie} 3B SCIENTIFIC PHYSICS U8431776. 3B SCIENTIFIC PHYSICS U8431776 12 pages. Apparatus for demonstrating waves along a cord

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3B SCIENTIFIC PHYSICS U8431776 Fiche d'instruction

3. Operation

The following additional equipment is needed to

carry out the experiments:

1 DC motor

1 Sine-wave generator

1 Transformer, 12 V, 25 VA

Experiment leads

3.1 Setting up

•

Set up the experiment as shown in Figure 1.

•

Insert the DC motor into the left-hand rod

socket and secure it.

•

Screw the two stand rods together, insert into

the right-hand socket, and secure them.

•

Fix the two universal clamps to the rods.

•

Push the pulley onto an axle-rod, secure it with

the axle clip, and fix it in the lower universal

clamp.

•

Fix the second axle rod in the upper universal

clamp and suspend the dynamometer from it.

•

Attach the elastic cord to the DC motor, pass it

under the pulley then up to attach it to the

dynamometer.

•

Adjust the height of the pulley so that the

elastic cord runs parallel to the base-plate.

Elwe Didactic GmbH • Steinfelsstr. 6 • 08248 Klingenthal • Germany •

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany •

U8552330

U8533550

U8475430-230

U8475430-115

Fig. 1 Experiment set-up

Subject to technical amendments

•

Connect the DC motor to the sine-wave

generator and connect the latter to the

transformer.

3.2 Experiment procedure

•

Set switches S2 and S3 of the sine-wave

generator to the "generator" position (right).

•

Apply no tension to the cord other than by

means of the dynamometer.

•

Adjust the frequency of the sine-wave

generator until a standing-wave vibration with

four peaks and troughs (two each) settles in.

Use the amplitude control to make fine

adjustments.

The wavelength is now half the length of the cord.

•

Move the dynamometer higher up the rod until

the tension is four times the previous value.

The band now vibrates with just one peak and one

trough. The wavelength is therefore equal to the

length of the band.

The following parameters are found to give good

results:

Frequency: 42-43 Hz, initial cord tension: 0.5N.