# How Does Skier Speed Affect Wave Frequency and Wavelength?

• mmiller39
In summary, the problem is trying to determine the speed and wavelength of a water wave based on the behavior of a water-skier. The skier springs upward at different intervals depending on the direction she is skiing in relation to the wave's movement. The speed of the skier is faster than the speed of the wave. To solve this, one must calculate the wavelength of the wave from the skier's perspective in each direction and use that information to determine the speed and wavelength of the wave.
mmiller39
I am trying to work through this problem to no avail.

## Homework Statement

A water-skier is moving at a speed of 12.5 m/s. When she skis in the same direction as a traveling wave, she springs upward every 0.498 s because of the wave crests. When she skis in the direction opposite to that in which the wave moves, she springs upward every 0.305 s in response to the crests. The speed of the skier is greater than the speed of the wave. Determine (a) the speed and (b) the wavelength of the wave.

## Homework Equations

we know that v = wavelength/ period

and that wavelength equals V/f

## The Attempt at a Solution

I am having trouble deriving period from the given data. I know that the speed of the wave is propotional to the speed of the water skier, but I am not sure about the correct ratio to use.

any help is appreciated.

-Matt

The speed of the wave has nothing to do with the speed of the water skier. The rate at which the skier hits the wave peaks is related to both the speed of the skier and the wave speed. What is the apparent wavelength of the water wave from the skier's point of view ("reference frame") in each direction? And how can you use those wavelengths to get you your answers?

Hello Matt,

I can understand your confusion with this problem. Let's break it down step by step.

First, we know that the speed of the water skier (12.5 m/s) is greater than the speed of the wave. This means that the skier is catching up to the wave, causing her to spring upward every 0.498 s when skiing in the same direction as the wave. In this case, the wave crests are occurring more frequently due to the skier's speed.

Next, when the skier is skiing in the opposite direction of the wave, she is moving away from the wave and therefore the wave crests are occurring less frequently, causing her to spring upward every 0.305 s.

Now, we can use the equation v = λ/T, where v is the speed of the wave, λ is the wavelength, and T is the period. We can also use the equation λ = v/f, where f is the frequency of the wave. Since we know that the skier is skiing at a constant speed of 12.5 m/s, we can use this value for v in both equations.

For the first scenario (skier skiing in the same direction as the wave), we can use T = 0.498 s and solve for λ using the equation v = λ/T. This gives us a wavelength of approximately 6.28 m.

For the second scenario (skier skiing in the opposite direction of the wave), we can use T = 0.305 s and solve for λ using the equation v = λ/T. This gives us a wavelength of approximately 3.82 m.

So, the speed of the wave in both scenarios is the same (since the skier is moving at a constant speed), but the wavelength changes depending on the direction of the skier's movement.

I hope this helps you understand the problem better. Good luck with your studies!

Best,

## 1. What is a wave?

A wave is a disturbance that travels through a medium, transferring energy from one point to another without permanently displacing the medium itself.

## 2. What is the speed of a wave?

The speed of a wave is the distance it travels per unit time. It is determined by the properties of the medium through which the wave is traveling, such as density, elasticity, and temperature.

## 3. How is wave speed related to wavelength and frequency?

The speed of a wave is directly proportional to its wavelength and frequency. This means that as the wavelength or frequency increases, so does the wave speed.

## 4. What factors affect the speed of a wave?

The speed of a wave can be affected by several factors, including the properties of the medium, the amplitude of the wave, and the medium's temperature and pressure.

## 5. How can the speed of a wave be calculated?

The speed of a wave can be calculated by dividing the wavelength by the period (time it takes for one complete wave cycle) or by multiplying the wavelength by the frequency. The formula for wave speed is v = λ/T = λf.

• Introductory Physics Homework Help
Replies
7
Views
2K
• Introductory Physics Homework Help
Replies
7
Views
901
• Introductory Physics Homework Help
Replies
16
Views
3K
• Introductory Physics Homework Help
Replies
1
Views
53K
• Introductory Physics Homework Help
Replies
2
Views
4K
• Introductory Physics Homework Help
Replies
5
Views
5K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
2K
• Introductory Physics Homework Help
Replies
7
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
2K