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Waves on the Sea

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Waves on the Sea

by David@VeritasPrep » Thu Aug 26, 2010 1:40 pm
Perhaps this one is more difficult...as always thanks in advance for the comments. The last question (foreign language) is going to be edited based on comments received.


"Ocean waves are actually a circular movement of the water both above and below the surface. Boaters and swimmers see and feel the portion of the wave that is above the surface. As long as the wave is in the deep ocean it will usually not fall in on itself, known as "breaking." When the bottom of the ocean becomes shallower - specifically when the depth of the water is less than 1.3 times the height of the wave - the wave will break. This occurs because the circular motion of the wave below the water cannot continue and the portion of the wave above the surface builds up until it collapses.

If the statements above are true, which of the following can be inferred?

A) Waves occurring in the deeper parts of the ocean are not dangerous because they usually do not break.

B) Shallow water is the only mechanism that causes waves to break.

C) Swimmers and boaters should avoid areas where waves are breaking.

D) It may be possible to estimate the depth of shallow ocean waters based on the height of breaking waves.

E) Waves occurring in freshwater lakes do not reach the same height as waves in the ocean.
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by uwhusky » Thu Aug 26, 2010 1:46 pm
[spoiler]Answer is D for me.

A, B and C are out of scope, E requires a little more assumptions in both the freshwater lake and ocean in order to be established.

D has the right tone, "may be possible", and given the stimulus that discuss wave breakage, I think D is almost indisputable. [/spoiler]
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by beatthegmatinsept » Thu Aug 26, 2010 1:48 pm
David@VeritasPrep wrote:Perhaps this one is more difficult...as always thanks in advance for the comments. The last question (foreign language) is going to be edited based on comments received.


"Ocean waves are actually a circular movement of the water both above and below the surface. Boaters and swimmers see and feel the portion of the wave that is above the surface. As long as the wave is in the deep ocean it will usually not fall in on itself, known as "breaking." When the bottom of the ocean becomes shallower - specifically when the depth of the water is less than 1.3 times the height of the wave - the wave will break. This occurs because the circular motion of the wave below the water cannot continue and the portion of the wave above the surface builds up until it collapses.

If the statements above are true, which of the following can be inferred?

A) Waves occurring in the deeper parts of the ocean are not dangerous because they usually do not break.

B) Shallow water is the only mechanism that causes waves to break.

C) Swimmers and boaters should avoid areas where waves are breaking.

D) It may be possible to estimate the depth of shallow ocean waters based on the height of breaking waves.

E) Waves occurring in freshwater lakes do not reach the same height as waves in the ocean.
Nice, tricky one there David.
Choice A and B seem like trap choices, the easy ones that most people would fall for. Choice C is too much generalizing, so I'd eliminate that. Choice E talks about freshwater lakes, which are lot mentioned anywhere, so eliminate that too.
I'd for D.
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by SeemaSkl » Thu Aug 26, 2010 3:32 pm
I will go for D also. This is the only choice that can be logically inferred.
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by reply2spg » Thu Aug 26, 2010 5:12 pm
Dear David,

I felt this one as easy, may be I have read the passage very very carefully and may be I had pre-phrased the answer. Just curious to know that what would be the level of this question. Ok here is my analysis. Please let me know if it is correct
David@VeritasPrep wrote:Perhaps this one is more difficult...as always thanks in advance for the comments. The last question (foreign language) is going to be edited based on comments received.


"Ocean waves are actually a circular movement of the water both above and below the surface. Boaters and swimmers see and feel the portion of the wave that is above the surface. As long as the wave is in the deep ocean it will usually not fall in on itself, known as "breaking." When the bottom of the ocean becomes shallower - specifically when the depth of the water is less than 1.3 times the height of the wave - the wave will break. This occurs because the circular motion of the wave below the water cannot continue and the portion of the wave above the surface builds up until it collapses.

If the statements above are true, which of the following can be inferred?

A) Waves occurring in the deeper parts of the ocean are not dangerous because they usually do not break. - We are nowhere talking about whether the waves are dangerous. So eliminate this one.

B) Shallow water is the only mechanism that causes waves to break. - Though argument says that shallow water breaks the wave, it is not mentioned that this is the only reason. This is very extreme option, eliminate

C) Swimmers and boaters should avoid areas where waves are breaking. - Why should they? This is very absurd option and I was just laughing. If we consider this option then no swimmer and boater could go into the ocean. Since we have shallow water bed at the beach and swimmer and boater go into the sea from beach only. So this can not be true. In passage perspective this is no where mentioned and we can not infer the same from any sentence.

D) It may be possible to estimate the depth of shallow ocean waters based on the height of breaking waves. - aha!! If I know the height of the wave then using the formula I can decide the upper limit of the depth of the ocean bed and I can predict the depth of the water bed. This is specified in the passage. 'depth of the water is less than 1.3 times the height of the wave'

E) Waves occurring in freshwater lakes do not reach the same height as waves in the ocean. - New information. Fresh water lakes are not even mentioned in the passage, eliminate
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by ankurmit » Thu Aug 26, 2010 10:49 pm
I will go with D
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by David@VeritasPrep » Fri Aug 27, 2010 3:56 am
OA is D

The correct answer must be true, while incorrect answers could be false.

Choice A could be false because the stimulus never discusses the danger posed by deep ocean waves.

Choice B also goes beyond what is discussed in the stimulus; the stimulus indicates shallow water is one cause of waves breaking but maybe not necessarily the only cause.

Choice C uses the word "should" which is usually an indicator of reaching beyond what must be true. The stimulus does not say anything about what portions of the ocean should be avoided.

Choice E also goes beyond the stimulus by bringing freshwater lakes into the discussion. It may certainly be true that waves on lakes are not as big as those in the ocean, but this may also be false precisely because it is not discussed by the stimulus.

Choice D is the correct answer as the stimulus provides ample reasons why it may be possible to estimate the depth of water based on the height of breaking waves.


As to the difficulty of the problem, probably average or a little above. reply2spg, I find that inference questions can be a little easier for me than others because they present such a good opportunity for process of elimination.

Nice job guys!
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by diebeatsthegmat » Sat Aug 28, 2010 6:48 pm
David@VeritasPrep wrote:OA is D

The correct answer must be true, while incorrect answers could be false.

Choice A could be false because the stimulus never discusses the danger posed by deep ocean waves.

Choice B also goes beyond what is discussed in the stimulus; the stimulus indicates shallow water is one cause of waves breaking but maybe not necessarily the only cause.

Choice C uses the word "should" which is usually an indicator of reaching beyond what must be true. The stimulus does not say anything about what portions of the ocean should be avoided.

Choice E also goes beyond the stimulus by bringing freshwater lakes into the discussion. It may certainly be true that waves on lakes are not as big as those in the ocean, but this may also be false precisely because it is not discussed by the stimulus.

Choice D is the correct answer as the stimulus provides ample reasons why it may be possible to estimate the depth of water based on the height of breaking waves.


As to the difficulty of the problem, probably average or a little above. reply2spg, I find that inference questions can be a little easier for me than others because they present such a good opportunity for process of elimination.

Nice job guys!
very nice question to practice, Davis
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by mundasingh123 » Wed Jan 05, 2011 3:11 am
Hi David ,I agree with u on that Inference questions could make the POE easier.
I was still doubtful abt D being the right answer .
Can you just clarify a few things in the stimulus.
The stimulus says
1)when the depth of the wave becomes less than 1.3 times the height of the wave,the wave will break
2)Then the stimulus goes on to say :This is because the circular movement can longer take place below the surface.The wave continues to build up above the surface until it collapses.
So The wave will continue to rise after it reaches the breaking point where the depth becomes less than 1.3 times the height of the wave above the surface.
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by David@VeritasPrep » Wed Jan 05, 2011 12:34 pm
mundasingh -

I think what you are saying is that the wave continues to build up after it reaches the breaking point. This would make it harder to estimate the depth of the ocean at that point if the waves built up to varying heights.

The stimulus does say "specifically when the depth of the water is less than 1.3 times the height of the wave - the wave will break." This means that the wave is continuing to try to roll but the part beneath the water cannot roll due to the shallow water so that top of the wave curls over. The stimulus is intended to indicate that this happens very close to the 1.3 times mark and so if you see a ten foot wave breaking you would know that the depth of the water is around 13 feet.

Does that clarify or do you think I should modify the stimulus?
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by mundasingh123 » Thu Jan 06, 2011 3:52 am
Hi David,
Thanks for the Reply.
I just wished to confirm that the way i interpreted the stimulus is how anyone will interpret after reading the stimulus.
The way i interpreted the stimulus is
Sttmnt 1 : The moment the depth of the sea reaches less 13 ft assuming that the height of the wave is 10ft,the wave will break.
This gives the impression that 10 ft will be the maximum ht of the wave and the wave will fall at this point.

Sttmnt 2: The portion of the wave above the surface will continue to roll while the portion below the surface is not able to roll .
so This gives the impression that the ht of the wave will increase (will continue to build up until it collapses )to more than 10 ft and subsequently decrease.

So do u think whether interpretation makes any sense .
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by David@VeritasPrep » Thu Jan 06, 2011 8:23 am
That sounds about right! So yes, wave is not exactly at 10 feet, a little higher as it builds and then lower as it collapses. You have a very good understanding of this.

I hope that the "estimnate" helps out in the answer choice we would not be able to say exactly the depth but estimate around a certain depth of 13 feet (plus or minus).

I can still edit a few words here if you think the answer choice and stimulus don't match up exactly. Sometimes one or two words make all the difference.
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by mundasingh123 » Thu Jan 06, 2011 10:44 am
David,Thanks for the question Firstly.
I just pondered over the implication of the words " will continue to " .Even then, i was able to zero down to the right answer .I thought the word "estimate" neans to to have a definite vaue without approximation.Do u mean the word "estimate " refers to a an approximate value .
.It was a very Good question .Thanks.
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