physics problem

[nrddct]

If ocean waves strike the shore every 3 sec and the horizontal distance between adjacent crests and troughs is 1 meter what is the average speed of the waves?

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[dsprague12]

If ocean waves strike the shore every 3 sec and the horizontal distance between adjacent crests and troughs is 1 meter what is the average speed of the waves?

velocity = frequency x wavelength

 

[vmp200]

If ocean waves strike the shore every 3 sec and the horizontal distance between adjacent crests and troughs is 1 meter what is the average speed of the waves?

v = f*wavelength.
v = (1/3)*(2) = 2/3 m/sec??

not sure if its more complicated than that.

 

[Mister Pie]

v = f*wavelength.
v = (1/3)*(2) = 2/3 m/sec??

not sure if its more complicated than that.

No, that's what I was thinking as well. I'm not sure if the wavelength is supposed to be 1 or 2 m though. If they meant it as 1 m between adjacent crests AND adjacent troughs, then it's 1 m. If they mean 1 m betweeen a crest and a trough, than it's 2m. Man, I hate world problems!

 

[NapeSpikes]

I don't understand what you're saying...why would it ever be 1m?

 

[yzf600]

VMP200 is right.


velocity = frequency x wavelength


frequency = (cycles/second) = 1 wave/3 seconds = 1/3 hz

wavelength = 2m...........why? it says the distance between adjacent crest and trough is 1m....this is only 1/2 of a full wavelength. peak to peak or trough to trough is a full wavelength, so peak to trough is just 1/2.

so....

v= (1/3) * 2m = 2/3 m/s

 

[gotgame83]

haha, i remember this question. I got so mad. In the end i believe i picked two meters but i really wanted to say 1 meter based on how it was phrased.

 

[topdogg82]

yea i remember this one and the phrasing on this question definitely sucked

 

[jon0013]

yea i remember this one and the phrasing on this question definitely sucked

wavelength is 2m because the 1m between crest and trough is L....2L=lambda...so therefore wavelength is 2m...can someone verify?

 

[yzf600]

wavelength is 2m because the 1m between crest and trough is L....2L=lambda...so therefore wavelength is 2m...can someone verify?

yea that's right....

L = a half-wavelength, and 2L would = a full wavelength

 

[Mister Pie]

wavelength is 2m because the 1m between crest and trough is L....2L=lambda...so therefore wavelength is 2m...can someone verify?

Yup. But, if you read it differently, it looks like they're saying that crests are 1 m apart (which means troughs are 1 m apart). If that were the case, the wavelength would be 1m, which is what I was talking about earlier.

 

[Sicilian]

The key word in the question is adjacent. The 1 m refers to a crest and trough that are right next to each other. So the wavelength - which is the distance between adjacent crest and crest, or trough and trough - has to be 2 m. In other words, any particle on a crest or trough of the wave would have to move 2 m before it returned to its old position. Actually, the wavelength is valid for any two consecutive points on the wave (meaning two points that are the same distance from a crest or trough), but if you think about it, its easier to measure distance with a crest or trough as your reference point, because the slope there is zero (horizontal tangent).

 

[NapeSpikes]

Ohhh, now I see the confusion. I would think that if they meant for the wavelength to be 1m, the question would have read "..adjacent crests is 1m" or "..adjacent crests and adjacent trophs are each 1m..." How it reads now, it seems pretty clear to be 2m.