# 0.4 Transverse waves  (Page 4/10)

 Page 4 / 10

A cork on the surface of a swimming pool bobs up and down once every second on some ripples. The ripples have a wavelength of $20\phantom{\rule{2pt}{0ex}}\mathrm{cm}$ . If the cork is $2\phantom{\rule{2pt}{0ex}}\mathrm{m}$ from the edge of the pool, how long does it take a ripple passing the cork to reach the edge?

1. We are given:

• frequency of wave: $f=1\phantom{\rule{2pt}{0ex}}\mathrm{Hz}$
• wavelength of wave: $\lambda =20\phantom{\rule{2pt}{0ex}}\mathrm{cm}$
• distance of cork from edge of pool: $D\phantom{\rule{0.166667em}{0ex}}=2\phantom{\rule{2pt}{0ex}}\mathrm{m}$

We are required to determine the time it takes for a ripple to travel between the cork and the edge of the pool.

The wavelength is not in SI units and should be converted.

2. The time taken for the ripple to reach the edge of the pool is obtained from:

$t=\frac{D}{v}\phantom{\rule{4pt}{0ex}}\phantom{\rule{4pt}{0ex}}\phantom{\rule{4pt}{0ex}}\phantom{\rule{4pt}{0ex}}\phantom{\rule{4pt}{0ex}}\left(\text{from}\phantom{\rule{4pt}{0ex}}v=\frac{D}{t}\right)$

We know that

$v=f·\lambda$

Therefore,

$t=\frac{D}{f·\lambda }$
3. $20\phantom{\rule{0.166667em}{0ex}}\mathrm{cm}=0,2\phantom{\rule{0.166667em}{0ex}}\mathrm{m}$
4. $\begin{array}{ccc}\hfill t& =& \frac{D}{f·\lambda }\hfill \\ & =& \frac{2\phantom{\rule{0.166667em}{0ex}}\mathrm{m}}{\left(1\phantom{\rule{0.277778em}{0ex}}\mathrm{Hz}\right)\left(0,2\phantom{\rule{0.166667em}{0ex}}\mathrm{m}\right)}\hfill \\ & =& 10\phantom{\rule{0.166667em}{0ex}}\mathrm{s}\hfill \end{array}$
5. A ripple passing the leaf will take $10\phantom{\rule{2pt}{0ex}}\mathrm{s}$ to reach the edge of the pool.

The following video provides a summary of the concepts covered so far.

## Waves

1. When the particles of a medium move perpendicular to the direction of the wave motion, the wave is called a $.........$ wave.
2. A transverse wave is moving downwards. In what direction do the particles in the medium move?
3. Consider the diagram below and answer the questions that follow:
1. the wavelength of the wave is shown by letter .
2. the amplitude of the wave is shown by letter .
4. Draw 2 wavelengths of the following transverse waves on the same graph paper. Label all important values.
1. Wave 1: Amplitude = 1 cm, wavelength = 3 cm
2. Wave 2: Peak to trough distance (vertical) = 3 cm, peak to peak distance (horizontal) = 5 cm
5. You are given the transverse wave below. Draw the following:
1. A wave with twice the amplitude of the given wave.
2. A wave with half the amplitude of the given wave.
3. A wave travelling at the same speed with twice the frequency of the given wave.
4. A wave travelling at the same speed with half the frequency of the given wave.
5. A wave with twice the wavelength of the given wave.
6. A wave with half the wavelength of the given wave.
7. A wave travelling at the same speed with twice the period of the given wave.
8. A wave travelling at the same speed with half the period of the given wave.
6. A transverse wave travelling at the same speed with an amplitude of 5 cm has a frequency of 15 Hz. The horizontal distance from a crest to the nearest trough is measured to be 2,5 cm. Find the
1. period of the wave.
2. speed of the wave.
7. A fly flaps its wings back and forth 200 times each second. Calculate the period of a wing flap.
8. As the period of a wave increases, the frequency increases/decreases/does not change.
9. Calculate the frequency of rotation of the second hand on a clock.
10. Microwave ovens produce radiation with a frequency of 2 450 MHz (1 MHz = ${10}^{6}$  Hz) and a wavelength of 0,122 m. What is the wave speed of the radiation?
11. Study the following diagram and answer the questions:
1. Identify two sets of points that are in phase.
2. Identify two sets of points that are out of phase.
3. Identify any two points that would indicate a wavelength.
12. Tom is fishing from a pier and notices that four wave crests pass by in 8 s and estimates the distance between two successive crests is 4 m. The timing starts with the first crest and ends with the fourth. Calculate the speed of the wave.

#### Questions & Answers

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
Draw a frame of reference with house A as the origin and write down the positions of houses B, C, D and E.