Physics of waves question

[[Tycho?]]

If t2 = 17.00 s for slinky (a), what is t1?''

 

That is all the information I have to complete this question, and I dont really know where to begin. t1 and t2 seem to be .16 of a full wavelenght apart, and the amplitude is given, but I can't seem to get any more useful information out of there. Or alternately, I dont know what to do with the information I do have. Any help on this would be appreciated. I doubt its actually very hard, but I really need some help on starting off.

[timo]

I think you can assume constant velocity for the wave. Take a look at the points (0,0), (3,0) and (6,0).

[timo]

I think you can assume constant velocity for the wave. Take a look at the points (0,0), (3,0) and (6,0).

 

Oh, and btw: You were a bit hasty/confused with your assumptions, I think (or you´re simply a lazy writer):

'] t1 and t2 seem to be .16 of a full wavelenght apart, [...']

Two times are 15 meters apart?

 

... and this reply was supposed to be an EDIT ...

[[Tycho?]]

I think you can assume constant velocity for the wave. Take a look at the points (0' date='0), (3,0) and (6,0).

 

Oh, and btw: You were a bit hasty/confused with your assumptions, I think (or you´re simply a lazy writer):

 

Two times are 15 meters apart?

 

... and this reply was supposed to be an EDIT ...[/quote']

 

Yeah so I got it, simply half the time t2 of course.

 

How does my assumption make the two times 15 meters apart? I'm not defending my assumption here, I dont know much about this sort of thing. So where did you get this 15 meters from?

[timo]

The point was that you said two times are a fraction of wavelength apart. But since time is measured in seconds and wavelength has the unit meters this could have been a hint already that something is wrong or at least incomplete with the statement. The 15 meters where just an arbitrary choice for a distance.

 

I simply stumbled over that statement because it made me think you have plotted three different waves.

 

EDIT: But on 2nd thought I think I know what you meant: Between t1 and t2 the wave has travelled that distance - I simply didn´t understand it initially.

[[Tycho?]]

The point was that you said two times are a fraction of wavelength apart. But since time is measured in seconds and wavelength has the unit meters this could have been a hint already that something is wrong or at least incomplete with the statement. The 15 meters where just an arbitrary choice for a distance.

 

I simply stumbled over that statement because it made me think you have plotted three different waves.

 

I meant that in that time the wave travelled a distance equal to that fraction of a wavelength. I still dont see what wrong with my assumption.

 

Boy, this homework is making me feel as dumb as a brick, even basic problem solving stuff I'm having trouble with. Maybe I'm tired or something.