Waves on water


by asaspades
Tags: homework question, mastering physics, water, wave, waves
asaspades
asaspades is offline
#1
Jan10-14, 06:40 PM
P: 10
1. The problem statement, all variables and given/known data

A water wave traveling in a straight line on a lake is described by the equation
[itex]y(x,t)=(3.75\,\text{cm})\cos(0.450\,\text{cm}^{-1}x+5.40\,\text{s}^{−1}t)[/itex]
where [itex]y[/itex] is the displacement perpendicular to the undisturbed surface of the lake.

How much time does it take for one complete wave pattern to go past a fisherman in a boat at anchor?

What horizontal distance does the wave crest travel in that time?
2. Relevant equations

[itex]\omega = 2\pi f[/itex]
[itex]k=\frac{2\pi}{\lambda}[/itex]

3. The attempt at a solution

This is part of an online test we were asked to submit. For the first part I got [itex]t=1.16\,\text{s}[/itex] which was correct. For the second part I got the wavelength as the answer, [itex]\lambda = \frac{2\pi}{0.0045} \approx 1396\,\text{m}[/itex]. However, the online assessment tells me that the correct answer is [itex]0.140\,\text{m}[/itex].

Can anyone explain where I went wrong?

(This is also question 15.10 in University Physics with Modern Physics International Edition, 13th Edition, if anyone should happen to have the solution manual to such a thing)
Phys.Org News Partner Science news on Phys.org
Internet co-creator Cerf debunks 'myth' that US runs it
Astronomical forensics uncover planetary disks in Hubble archive
Solar-powered two-seat Sunseeker airplane has progress report
haruspex
haruspex is offline
#2
Jan10-14, 08:07 PM
Homework
Sci Advisor
HW Helper
Thanks ∞
P: 9,216
Your error is in converting 0.450cm−1 to m-1. You've handled it as though converting from cm to m.


Register to reply

Related Discussions
Light waves, photons; sound waves, phonons; water waves, "hydrons"? Quantum Physics 5
Water waves slower in shallow water, why? General Physics 0
Water waves accelerate in deeper water. General Physics 3
Water Electrolysis and Water Dissociation with RF waves General Physics 1
why will ultrasonic waves not interfere with other sound waves in water? Introductory Physics Homework 1