The apparatus consists of an electrically driven tuning fork with fixed frequency that vibrates one end of a stretched string. The string passes over a pulley and is attached to a weight holder. The tension of the string and hence the velocity of the wave is adjusted by adding weights to the holder.

1.  Open the Worksheet and fill in the header information.

2.  Record in cell G12 the frequency, f, that is stamped on the vibrator.

3.  Measure the complete length of the cord and its mass, and enter them in cells D11:D12.

4.  Attach the cord to the vibrator-pulley assembly as indicated in Fig. 1-1.

5.  Start the vibrator by closing the switch in the electrical circuit and add just enough weights until a standing wave pattern with at least six loops (half-wave segments) is obtained. A standing wave pattern will be identified by relatively large amplitude of vibration at the antinodes.

DO NOT SWITCH THE LEADS TO A DIFFERENT POWER SUPPLY OR YOU MAY DAMAGE THE EQUIPMENT!

By measuring the distance (L) between the first and last nodes and dividing by the number of loops (N), the length of a loop and, consequently, the half wavelength is determined. The wavelength λ may therefore be calculated.

6.  Record the mass that is suspended (don't forget the mass of the holder) in cell B18 of the Data Table on the Worksheet.

7.  Record the total distance between the first and the last nodes, L, in cell D18.

8.  Continue to add weights until one fewer loop is produced and repeat the measurements of suspended mass and distance between first and last nodes. Record these values in cells B19 and D19.

9.  Repeat until only three loops are produced, filling out the Data Table cells B21 and D21.