Unit: Waves
Year: 1991 Question#: 40
Question: The diagram below shows the direction of water waves moving along path XY toward a barrier. Which arrow represents the direction of the waves after they have reflected from the barrier?
(1 )
(2 )
(3 )
(4 )
What is this question really asking?
Explanation by: John D (no last names)
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Answer 1
Incorrect
Answer 1 is incorrect because it indicates that although the waves are traveling toward the barrier at an angle, they are reflecting away perpendicaular to the barrier. This arrow actually represents the normal line.
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Answer 2
incorrect
ANswer 2 indicates the waves are reflecting away in the exact direction that they hit the barrier, which could only happen if the angle was perpendicular to the barrier, which it is not. return to top
Answer 3
correct
Answer three is correct because it shows the waves reflecting in the direction that is the angle of incident reflected over the normal line, which is the true behavior of the reflection of waves.
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Answer 4
incorrect
Answer 4 indicates that the waves passed through the barrier and continued to move in the same direction, which is not possible.
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What's this question really asking?
Do you know the properties of reflection?
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