A class uses a shallow ripple tank or a calibrated wave simulation to investigate a wave model. Available equipment and procedure options: Use a simulation or teacher-controlled linked source with phase settings and record the displacement amplitude at the midpoint line. Design an investigation of how the imposed phase offset between two equal sources affects the amplitude at a point equally distant from both sources. Include a reasoned hypothesis, an appropriate range, controls, repeat measurements, a results table or graph, and one specific limitation and safety measure. Do not invent experimental results.

Question

Accepted Answer

Vary the imposed phase offset between two equal sources; measure the amplitude at a point equally distant from both sources. Predict The equal-distance point should be largest in phase and smallest near opposite phase. Keep frequency, individual amplitude, point position and depth constant, repeat each setting, and use the evidence to test the prediction. State a testable research question linking the imposed phase offset between two equal sources to the amplitude at a point equally distant from both sources, rather than asking vaguely which arrangement is best. A suitable prediction is: The equal-distance point should be largest in phase and smallest near opposite phase. Justify that prediction scientifically: At equal distances, source timing determines whether the arriving displacements reinforce or cancel. This is a hypothesis to test, not a result that the experiment must produce. Use 0°, 90°, 180°, 270° and 360° as the planned independent-variable settings. Measure the response using the supplied equipment: Use a simulation or teacher-controlled linked source with phase settings and record the displacement amplitude at the midpoint line. Record quantities with units before calculating any derived result. Keep frequency, individual amplitude, point position and depth constant. This isolates the proposed cause; changing these conditions at the same time would allow competing explanations for any difference. Take at least three independent trials at each setting, resetting the apparatus each time. Tabulate the setting, individual responses and mean; plot the mean response against the changed quantity and show the range of repeated values. Evaluate this specific limitation: Unequal source amplitudes prevent complete cancellation; measure each source alone first. More repeats alone do not necessarily correct a biased method. Protect participants and equipment by this precaution: Keep water away from power supplies and use only teacher-approved low-voltage apparatus.

Changing the timing of linked sources

What a complete response should do

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