THE TIME LINE OF THE HISTORY OF OPTICS

http://www.tiki-toki.com/timeline/entry/211126/History-of-optics/#vars!date=1709-08-29_14:39:31!

WAVES PROPERTIES 1
Parts of a wave


Part 1

In the diagram below, identify the parts of a wave and then give a definition of each term.

Crest / trough / line of origin / wavelength / amplitude

5.-crest : A crest is the highest point of the wave.

2.-trough: A through is the lowest point of the wave

1.-line of origin : The line of origin is where the wave starts. Indicates the medium when is at rest.

3.-wavelength: The wavelength is the distance between one crest or trough to the next crest or trough.

4.-amplitude. Amplitud is how far the medium moves from rest position

Part 2

State which of the following waves you think has the highest frequency and which might have the lowest frequency. Explain the reasons for your selections.

wave #	crest	Trough	wavelength
1	1 cm	1 cm	2 cm
2	3.5 cm	3.5 cm	2.5 cm
3	0.5 cm	0.5 cm	3 cm
4	2 cm	2cm	0.5 cm

(Perhaps it would be useful for you to draw, on graph paper, the four different waves )

Highest frequency: 4 because have got the lowest wavelength, and that makes the wave to have a fast frequency.

Lowest frequency: 3 because have the highest wavelength, and that maks the wave have a long distance between one crest and the othe oner, and that's the frequency.

 

 

Waves

A wave is a disturbance that carries energy from one place to another.

Matter is NOT carried with the wave! A wave can move through matter (a media). If it must have a medium, it is called mechanical wave. If it can travel without a medium (such as in space), it is called electromagnetic wave.

Wave Types

1. Transverse waves: Waves in which the medium moves at right angles to the wave direction.
   

Parts of a transverse wave:

crest: the highest point of the wave

trough: the lowest point of the wave

2. Compressional (longitudinal) wave: Waves in which the medium moves back and forth in the same direction as the wave.
   

 Comparing transverse and longitudinal waves.

Wave properties depend on what type of energy makes the wave.

1. Wavelenght: The distance between one point on a wave and the exact same place on the next wave.
   
2. Frequency: How many waves go past a point in one second; measured in Hertz (Hz). The higher the frequency, the more energy in the wave.
   
3. Amplitude: How far the medium (crests and troughs, or compressions and rarefactions) moves from rest point/ line of origin (the place the medium is when not moving). The more energy a wave carries, the larger its amplitude.
   
4. Wave speed: Depends on the medium the wave is traveling in. This varies in solid, liquid and gases
   

Equation for calculating wave speed:

wave speed = wavelength (in m) x frequency (in Hz)

Problem:

If a wave has a wavelength of 2 m and a frequency of 500 Hz, what is its speed? Answer: wave speed = 1000m/s

WAVES

1. What are waves?
   Waves are disturbences that transported energy from one location to another location without tranportation of metal.
2. What are mechanical waves?
   Waves that require a material media to propagate from one point to another.
3. Why can waves propagate?
   Because they can propagate because of the the interaction forces between particles of a medium.
4. In the 'spring model', What do the springs represent?
   Spring represents the interaction forces between particles.
5. Can you specify two different types of mechanical waves?
   Transverse waves and longitudinal waves.
6. Can you define both kinds of waves?
   Transfer waves: they are waves which make the particles of medium vibrate perpendicular to the direction of wave motion.
   Longitudinal waves: waves make the particles of the medium vibrate parallel to the direction of the wave motion.
7. What is 'inertia'?
   Intertia is the tendency of objects to resist change in motion when are pushed or pull.
8. What kind of particles tend to have more inertia?
   Particles with greater mass tend have more inertia.
9. In longitudinal waves, are the particles of the medium carried along by the propagating waves?
   No they aren't.
10. In longitudinal waves, why don't the particles of the medium move at the same time?
    Because they have inertia.

EUGENE'S LIFE

Eugene is 23 years old. He's from Russia but he grew up in New York. He loves Latin dance and listening to contemporary sounds. He studied anthropology, at Amherst Colleg in Massachusetts.
Then he travelled around the world, he had lived in Russia, USA, France, Morocco, Serbia and now Spain; but he would like to live in Iceland.

His parents are from Russia. His mother is a teacher of musical theatre and his father is a symphonic conductor. 

POWERS

The power of a number shows you how many times to use the number in a multiplication.
It is written as a small number to the right and above the base number.
In this example: 8²= 8 × 8 = 64 (Another name for power is index or exponent)

In words: 8²could be called "8 to the power 2" or "8 to the second power", or simply "8 squared"
See more examples:
Example: 5³= 5x5x5=125 /

• In words: 5³ could be called “5 to the third power”, “5 to the power 3” or simply “ 5 cubed”
  

Exponents make it easier to write and use many multiplications.

• Example: 9⁶ is easier to write and read than 9x9x9x9x9x9
  

NEGATIVE EXPONENTS

A negative exponent means how to many times to divide. For example: 8 raised to -1 = 1/8= 0,125

MATHS

ROUNDING OFF DECIMALS

Rounding off decimals is a technique used to estimate or aproximate values. We can around to any place.ROUND UP AND ROUND DOWN increase one digit or decrease one digit. If the next place beyond where we are terminating the decimal is greater than or equal to five we round up.



How to round down: if the number to the right of our terminating decimal place is four or less.

For example:

a) 3,84 Here we have a decimal number to round off to tenths. First of all if the next place beyond where we are terminating the decimal is less than five we will round down. So if the number is 3,84 we must round down to the eight.

Well that is our first video, we hope that you will enjoy as much as we do, we are back to table, and this is our little presentation. See you guys!






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