A class uses a shallow ripple tank or a calibrated wave simulation to investigate a wave model. Available equipment and procedure options: Photograph incoming and reflected plane crests and draw directions perpendicular to each set of crests. Design an investigation of how the incident direction relative to a straight barrier normal affects the reflected wave direction measured from the normal. 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 incident direction relative to a straight barrier normal; measure the reflected wave direction measured from the normal. Predict The reflection angle should match the incident angle within measurement uncertainty. Keep barrier shape, depth, source frequency and observation scale constant, repeat each setting, and use the evidence to test the prediction. State a testable research question linking the incident direction relative to a straight barrier normal to the reflected wave direction measured from the normal, rather than asking vaguely which arrangement is best. A suitable prediction is: The reflection angle should match the incident angle within measurement uncertainty. Justify that prediction scientifically: A straight reflecting boundary changes propagation direction symmetrically about its normal. This is a hypothesis to test, not a result that the experiment must produce. Use 10°, 20°, 30°, 40° and 50° as the planned independent-variable settings. Measure the response using the supplied equipment: Photograph incoming and reflected plane crests and draw directions perpendicular to each set of crests. Record quantities with units before calculating any derived result. Keep barrier shape, depth, source frequency and observation scale 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: Overlapping crests can hide direction; analyse a pulse or distinguish incoming and outgoing frames. 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.

Steering a reflected ripple

What a complete response should do

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