Waves help (1 Viewer)

[Green Yoda]

halp plz

 

[InteGrand]

halp plz

1) For the maximum period, we would assume the wave has travelled as small as possible a fraction of a cycle in the time given. It looks to have travelled one-eighth of a cycle minimally, so the maximum period would be 8 * (0.35 s) = 2.8 s.

2) The frequency is the reciprocal of the period, so f = 1/T = 1/(2.8 s) = 0.35714... Hz = 0.36 Hz (2 sig. fig.).

3) The speed is v = fλ = λ/T. Clearly, the wavelength λ is 8 m (from the diagrams). So v = (8 m)/(2.8 s) = 2.85714.... = 2.9 m s^-1 (2 sig. fig.).

 

[Green Yoda]

1) For the maximum period, we would assume the wave has travelled as small as possible a fraction of a cycle in the time given. It looks to have travelled one-eighth of a cycle minimally, so the maximum period would be 8 * (0.35 s) = 2.8 s.

2) The frequency is the reciprocal of the period, so f = 1/T = 1/(2.8 s) = 0.35714... Hz = 0.36 Hz (2 sig. fig.).

3) The speed is v = fλ = λ/T. Clearly, the wavelength λ is 8 m (from the diagrams). So v = (8 m)/(2.8 s) = 2.85714.... = 2.9 m s^-1 (2 sig. fig.).

I dont understand here

 

[InteGrand]

I dont understand here

I think they want you to estimate how much of a cycle it has travelled visually (I don't see how else to do it). It looks like it has gone half-way towards that first peak, i.e. half-way towards a quarter of a cycle (since the first peak is a quarter of a cycle), which is hence one-eighth of a cycle.

 

[Green Yoda]

It seems to have moved about 1/4 th of the wav to me :/

 

[InteGrand]

It seems to have moved about 1/4 th of the wav to me :/

The end of the full cycle is when it comes back to the 8 m point in the first diagram (image a sine wave). It reaches like halfway between the start and the first peak. This is one-eighth of the way to the end.

 

[Green Yoda]

Oh yes I see

 

[Green Yoda]

Why 8 x 0.35 tho?

 

[InteGrand]

Why 8 x 0.35 tho?

Well it's a wave moving at a constant speed v (whose value we find at the end). So if it travels one-eighth of the wavelength in 0.35 seconds, it travels the full wavelength in 8 times this, i.e. 8*0.35 s. This value is then by definition the period T.

 

[Green Yoda]

oh yeah ofc..shit im so dumb
my brain doesnt work at this time haha
Thank You