Waves and Energy transfer problem ( am desperate)

• Alexielle
In summary: Hz.In summary, the problem involves a water wave and determining the fraction of a wavelength, the period, and the frequency based on the given information of 0.18 seconds for one fourth of the wavelength. The wavelength is 1/4 of the entire wavelength and the period is 0.72 seconds, with a frequency of 0.72 Hz.
Alexielle
Waves and Energy transfer problem (please am desperate)

Well, this is the problem that is breaking my head

the time needed for a water wave to change from the equilibrium level to the crest is 0.18s
a) what fraction of a wavelength is this?
b)what is the period of the wave?
c)What is the frequency of the wave?

I don't really understand this problem because of the little information they give me, and the fact that when i tried to check it with my brother's answer book, the wavelength gave 1/4, but they do not give a formula or say why the WL is 1/4..

A) Think a little, the whole wavelength would be measured from crest to crest. Let us use the sine wave as an example going from 0 to $$2\pi$$. Compare the distance from where the function equals zero (in your wave example, this is the equlibrium point) to where it equals 1 (again, in your example the crest) and then campare it to the entire wavelength of the function.

B) If it takes 0.18 seconds for one fourth of a wavelength to travel, how long does it take the whole wavelength?

C) Frequency is the inverse of the time, $$f=1/T$$.

Draw a picture! A wave starts from 0, goes up to its highest point, back down to 0, then down to its lowest point, then back up to 0: four sections, each of the same length- the whole thing is one wave length. Since you given ONE of the 4 sections (from 0 up to its highest point) you are given 1/4 of the entire wavelength.

Since 1/4 of the entire wavelength takes 0.18s, the entire wavelength will take
4(0.18)= 0.72 s, the period of the wave.

As theCandyman said, the frequency is 1 over the period: 1/0.72 "cycles per second"

1. What is the difference between mechanical and electromagnetic waves?

Mechanical waves require a medium to travel through, such as sound waves in air or water waves in water. Electromagnetic waves, on the other hand, can travel through a vacuum and do not require a medium. Examples include light waves and radio waves.

2. How does energy transfer occur in waves?

In all types of waves, energy is transferred from one point to another through the movement of particles or fields. In mechanical waves, energy is transferred through the vibration of particles in the medium, while in electromagnetic waves, energy is transferred through oscillating electric and magnetic fields.

3. What is the relationship between wavelength, frequency, and energy?

Wavelength and frequency are inversely proportional, meaning that as one increases, the other decreases. This relationship is described by the equation c = λν, where c is the speed of light, λ is the wavelength, and ν is the frequency. Energy is directly proportional to frequency, so as frequency increases, so does the energy of the wave.

4. How do waves transfer energy without physically moving matter?

Waves transfer energy through the movement of particles or fields without physically displacing the particles themselves. This is because the particles in a medium only vibrate back and forth, but do not travel with the wave. In electromagnetic waves, energy is transferred through oscillating electric and magnetic fields which do not require physical movement.

5. Can energy be lost during the transfer of waves?

Yes, energy can be lost during the transfer of waves. This is due to factors such as friction, absorption, and scattering, which can cause a decrease in the amplitude (intensity) of the wave. Additionally, in some cases, energy may be converted into other forms, such as thermal energy, during the transfer of waves.

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