Wave Speed uDu

Your task in this uDu is to use OHEC and determine how water depth affects the speed of water waves. Your team will submit its findings on the Wave Speed uDu Report.

STEP 1: Based on your previous OBSERVATIONS of waves, make a HYPOTHESIS. As a group, discuss and decide whether deeper water makes waves faster or slower.

STEP 2: Design an EXPERIMENT with a method for measuring wave speed using the following equipment:

Wave Tank (across two desks lengthwise)

Meter StickTimer Paddle

Ruler Bobber Plastic cup

Bucket for filling Siphon tube for emptying

Wave Speed uDu

STEP 3: Do your EXPERIMENT. Collect, analyze and plot your data. At a minimum, measure wave times at each of three depths. Do more if you have time.

STEP 4: Reach a CONCLUSION about whether your hypothesis was right. Be sure your conclusion is supported by your data and plot.

THIS ISN’T A WATERPARK AND YOU AREN’T 5 YEARS OLD.

DO NOT SPLASH WATER OUT OF THE GUTTERS!

Wave Speed uDu

CAUTIONS:

Beware of sharp edges on the gutters!

Short, quick pushes make the best waves. Long, slow pushes make messes — and an unhappy Dr. V

On clean up: Be sure to siphon out the gutters almost completely before pouring water into sink. The gutters buckle easily.

Wave Speed uDu

EXTRA OBSERVATION (if time permits):

Use the plastic cup as a plunger (up & down) at one end of your tank to make repeated waves. Figure out whether the waves get longer or shorter as they get more frequent.

Length of WaveCup

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Wave Speed uDu: Follow-up

METHOD:

Measure time T required for single wave crest to travel distance D. Speed = D / T.

Details: Multiple trials? Metric units? Synchronize timing? Measure depth? Detect end of motion? etc. !

D

Wave Speed uDu: Follow-up

KEY OBSERVATIONS — more on these later!

• Wave speed increases in deeper water.

• Bobber bobbed but did NOT move forward with wave!

• Waves got shorter as they got more frequent.

D

Depth (cm)