# 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

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
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Source:  OpenStax, Physics - grade 10 [caps 2011]. OpenStax CNX. Jun 14, 2011 Download for free at http://cnx.org/content/col11298/1.3
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