SCIE 111 Integrated Sciences I

1. SCIE 111 Integrated Sciences I Fac. Manuel Laureano

2. Final presentation members MajaHamoui Nancy Cortes Tatiana Pizarro Sara J Chaya Alvaro Rodriguez

3. Properties of Waves

4. Properties of Waves • Amplitude: • Wavelength: • Period: • Frequency: • Speed: • the height of the wave, measured in meters. • the distance between adjacent crests, measured in meters. • the time it takes for one complete wave to pass a given point, measured in seconds. • the number of complete waves that pass a point in one second, measured in inverse seconds, or Hertz (Hz). • the horizontal speed of a point on a wave as it propagates, measured in meters / second.

5. Properties of Waves Not all of these properties are independent; one has the relations: Period = 1 / frequency Speed = wavelength / period = wavelength x frequency

6. Properties of Waves

7. Properties of Waves

8. Wave phenomena • Refraction • Dispersion • Interference of Waves • Diffraction • Double Slit Experiment Revisited • The Doppler Effect.

9. Wave phenomena Sound is the most common example of waves that we encounter in our everyday life. A sound wave is caused by the vibration of air molecules in between the source and the listener; this is a clear example of waves transferring energy from one point to another without the transfer of matter.

10. Refraction of Waves • Refraction is very easily understood within the wave model of light if one recalls that light slows down as it enters a denser medium. If you imagine, a long wave front approaching water from the air, as shown below.

11. Dispersion of white light: in a prism • Another aspect of light that is quite common is the breaking up of white light into its constituent colors. For example, if a beam of white light enters a glass prism, as shown in the Figure below, what emerges from the other side is a spread out beam of many colored light.

12. For constructive interference, the waves meet in phase, i.e. so that the crests of each wave coincide. In destructive interference, the waves meet out of phase, so that the crest of one wave coincides with a trough of the other wave, and they cancel each other out.

13. The final property of light we discuss is interference, a phenomenon that occurs when two light beams meet. Depending on the nature of the light beams and when they meet, the two beams might enhance each other, to give a brighter beam, or they might interfere in a way that makes the total beam less bright. The former is called constructive interference, whereas the latter is called destructive interference. Double slit interference

14. Interference effects Plane and Circular The Doppler Effect

15. Visible spectrum MajaHamoui

16. Visible spectrum • The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm.

17. In terms of frequency, this corresponds to a band in the vicinity of 400–790 THz. A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum.

19. Visible wavelengths also pass through the "optical window", the region of the electromagnetic spectrum that passes largely unattenuated through the Earth's atmosphere. Clean air scatters blue light more than wavelengths toward the red, which is why the mid-day sky appears blue. The human eye's response is defined by subjective testing, but atmospheric windows are defined by physical measurement.

20. Visible spectrum The "visible window" is so called because it overlaps the human visible response spectrum. The near infrared (NIR) windows lie just out of the human response window, and the Medium Wavelength IR (MWIR) and Long Wavelength or Far Infrared (LWIR or FIR) are far beyond the human response region.

21. On the left is ultraviolet or UV radiation that can be found mainly in solar radiation is produced in electric arcs and by some specialized devices such as UV fluorescent tubes, also called black light. On the right is the infrared radiation, the so-called heat radiation or IR. All bodies emit radiation energy characteristics of matter, and the maximum exponent that occurs in the infrared.

22. Many species can see light with frequencies outside the "visible spectrum," which is defined in terms of human vision. Bees and many other insects can see light in the ultraviolet, which helps them find nectar in flowers. Plant species that depend on insect pollination may owe reproductive success to their appearance in ultraviolet light, rather than how colorful they appear to humans. Birds, too, can see into the ultraviolet (300–400 nm), and some have sex-dependent markings on their plumage, which are only visible in the ultraviolet range

23. The perception of color depends on the wavelength when the light strikes a body, it better reflects some wavelengths than others. This to be perceived by the human eye determines the characteristic color of the body. Of course, the perception of each color varies from person to person.

24. In 1666, Isaac Newton made ​​his first experiments on the colors produced by passing a narrow beam of light through a prism. Newton defined the spectrum as the orderly arrangement of colors from violet to red. He believed that some imperfection in the glass was the cause of the spectrum, and to verify his guess, he produce a spectrum through a prism with impinges, but oriented inversely (opposite). If the spectrum was caused by irregularities in the second prism, it should have increased the widening of the colors. Instead, it formed a point of white light. After further experiments, he became convinced that white light consists of colors. Today we know that each color in the spectrum is associated with a specific wavelength.

25. At the beginning, we said that the rainbow is a consequence of the decomposition of light. Now, in simple explanation, we say that a rainbow forms when sunlight passing through raindrops. Sunlight is composed of all colors, which produced mixed lighting. When sunlight penetrates the water droplets, it’s reflected in the interior surfaces. While passing through drops, the light is separated into its component colors, producing an effect very similar to a prism. Obviously, this dispersion occurs in all the droplets that are exposed to sunlight In more scientific way, the rainbow is an optical phenomenon produced by the scattering of sunlight when it is refracted and reflected in the drops of rain. This sunlight is separated into components, resulting in a bright arc formed by the various colors of the rainbow. The color red is refracted the least and is on the outside of the arc, turning towards the interior, orange, yellow, green, blue, indigo and violet.

26. How Energy Is Transmitted

27. How Energy Is Transmitted • Energy is an electrical charge that is composed of sub-atomic particles . • The matter is influenced by electromagnetic fields ; the interactions between the electric charge and field is the source of the four fundamental interactions. • The particle that carries the information of these electromagnetic interactions is the photon, which takes time.

28. How Energy Is Transmitted • The amount of time a photon takes is determined by T=C/D; where C is the speed of light in the medium which transmits, while D is the distance between the charges. • Energy is manifested in many phenomena, including mechanical, thermal, light, and chemical. • Energy can be naturally observed in the rays that are produced by electrical discharges of energy transfers between the ionosphere and the ground’s surface.

29. Different Forms of Energy • Thermal Energy: The sum of the kinetic and potential energy of the particles in an object due to their random motion. Example: the liquid in a thermometer expands when its temperature increases.

30. Different Forms of Energy Chemical Energy: Is the energy stored in chemical bonds. Example: During photosynthesis, green plants use radiant energy from the sun to produce chemical compounds which are eaten by humans.

32. Different Forms of Energy • Radiant Energy: Is energy that travels in the form if waves. The sunlight that reaches earth is radiant energy that travels through space as electromagnetic waves. Example: radio waves, microwaves, light and x-ray waves.

33. Different Forms of Energy • Electrical Energy: Is carried by electrical currents. Example: Cd players

34. Different Forms of Energy • Nuclear Energy: Is when changes occur in the nuclei of an atom.

35. Different Forms of Energy • Kinetic Energy: Depends on mass and speed Example: a bowling or tennis ball in movement.

36. Different Forms of Energy • Potential Energy: Is stored energy in an object that is not in motion due to its position . Example: When you lift a back pack you cause its position to change.

37. Energy

38. Links • 'The God Particle': The Higgs Boson • http://youtu.be/1_HrQVhgbeo • Electromagnetic Spectrum: Radio Waves • http://youtu.be/al7sFP4C2TY • Sound, Vibration, Wave Characteristics • http://youtu.be/dbeK1fg1Rew

39. References • http://www.school-for-champions.com/science/waves.htm • http://theory.uwinnipeg.ca/mod_tech/node119.html • http://theory.uwinnipeg.ca/mod_tech/node124.html • http://theory.uwinnipeg.ca/mod_tech/node125.html