TAKS Objective 5

1. TAKS Objective 5 Heat, Waves and the Electromagnetic Spectrum

2. Waves - Energy carried by rhythmic disturbances Two types: 1. E.M. radiation move through empty space 2. Mechanical require a medium (air, water or any type of matter) for movement

3. Waves - 2 Types

4. Try this one: 10 Which label on the model represents a wavelength? F Q G R H S J T

5. All waves have similar properties Frequency- the number of vibrations per second or the speed of the movement of the vibrating particles Amplitude – the size of the movement of the vibrating particles Both are controlled by the disturbance that created the waves

6. Longitudinal or Compress ional Waves Vibrating particles move back and forth along the direction of the wave velocity The wave consists of compressions and rarefactions Ex. Sound Waves

7. Transverse Waves In Transverse Waves particles vibrate at right angles to the direction the wave travels. Ex. Electromagnetic Waves, water waves or wiggling rope.

8. Sound Waves are Compression Waves Sound is produced when a compression is made. It requires a producer and a medium to travel through. The more elastic the object, the faster sound travels.

9. Sound acts like other waves Echoes are reflected sound waves Sonar uses echoes to judge distance to obstructions Human hearing is 20-20,000 Hz. Below 10 Hz is infrasonic, and above 20,000 Hz is ultrasonic. Resonance occurs when one vibrating object sends compression waves that begin another object vibrating at the same frequency.

10. Sound Waves move through matter not through empty space. 32 One tuning fork is struck and placed next to an identical fork. The two forks do not touch. The second tuning fork starts to vibrate because of — F interference G the Doppler effect H resonance J standing waves

11. And the answer is? 38 At 0°C sound travels through air at a speed of 330 m/s. If a sound wave is produced with a wavelength of 0.10 m, what is the wave’s frequency? F 0.0033 Hz G 33 Hz H 330 Hz J 3300 Hz

12. Velocity of all waves - v=f ? f-frequency and ? is wavelength (distance between identical points on two consecutive waves) Reflection- bounce off barriers in regular ways Refraction- waves bend when speed changes by entering a different substance

13. Electromagnetic Spectrum Radiation comes in the form of vibrating or “throbbing bundles of energy” called photons The frequency of the vibrating electric charges determines which type and how much energy will be given off

14. The entire E.M. Spectrum in order from lowest to highest frequency Radio waves: AM and FM Microwaves: cooking Infrared: heat Visible: (ROYGBV) Ultraviolet: tanning Xrays: medical Gamma:

15. Nuclear Reactions Fusion occurs when two atoms combine to form a new element. The sun and other stars produces all of their energy through fusion. Two hydrogen atoms combine to form a Helium atom from the great gravitational forces and pressure in the sun’s core

16. Nuclear Reactions - Fission Fission is the splitting of nucleii of large atoms such as Uranium and Plutonium Produces large amounts of infrared radiation and other forms of E.M. Energy such as Gamma Rays Currently, it is the main form of Atomic Energy on Earth

17. Radiant Energy or Electromagnetic Energy (EM) All radiant energy travels at 3.0 x 108 m/sec in space or 186,000 miles/sec Velocity of a wave = wavelength x frequency Visible light is just one type of EM Energy

18. Movement of Waves When waves hit a barrier, they bounce of at the same angle that they were at when they hit. (Law of Reflection) They continue through a barrier break at the same pattern and speed they were at previously.

19. Increasing or Decreasing wave energy Constructive interference adds energy to the wave as the crest meets crest or trough meets trough. Destructive interference causes the wave to be slowed or stopped by crest meeting trough. It cancels the amplitude of the wave.

20. Thermal Energy A body contains internal KE due to the motion of its atoms ( they are constantly wiggling and jiggling) Thermal Energy is the total internal KE of a body Temperature is the average KE of a body

21. Heat- Transfer of Thermal Energy 1. Conduction-direct contact, a pot heating on a stove (solids) 2. Convection- heating by circulating fluids, (gas and liquid) heating from a fireplace And. . .

22. 3. Radiation – Transfer of Electromagnetic (E.M.) Energy Objects are heated when exposed to infrared radiation The suns heats the earth by sending infrared radiation along with other forms of E.M. energy 3.0 x 108 meters through empty space

23. 2 The primary way liquids and gases transmit heat is by the process of — F reflection G conduction H radiation J convection

24. F improve emission of infrared radiation G reduce the heat loss by convection currents H improve absorption of infrared radiation J reduce the heater’s conducting properties

25. Heat moves by conduction in solids since the particles are close together and vibrate. . . 43 Heat convection occurs in gases and liquids. Heat convection does not occur in solids because solids are unable to — A absorb heat by vibrating B transfer heat by fluid motion C emit radiation by reflecting light D exchange heat by direct contact

26. Your Turn!! 1. The transfer of heat by the movement of air currents in Earth’s atmosphere is an example of — A conduction B convection C radiation D fusion

27. 2. Which of the following would explain why this film works with a reduced amount of light? A The film reflects long wavelengths of light efficiently. B Fewer silver halide granules are present in the film. C The film refracts brighter light. D The photochemical reaction can occur in lower intensity light.

28. 3. Which of these tools is most useful in identifying the wavelengths of visible light? F Convex lens G Spectroscope H Microscope J Concave mirror

29. 4. The diagram shows waves approaching a barrier. Which pattern will be formed after the waves pass through the opening in the barrier?

30. 5. A guitar player is seated next to a piano. The piano player strikes an E key on the piano. The guitarist reports that this causes the E string on his guitar to vibrate. What is the name of this phenomenon? A Polarization B Resonance C Reflection D Diffraction

31. And the answers are. . . B: Air currents refers to convection. D: Photo refers to light, and images are made by a chemical reaction on the film. G: Spectrum waves are measured by a spectrascope. B: The parts of the wave which pass through spread out again, and keep the same pattern. B: Sound moves through particles such as air, which when it hits something with the correct frequency will begin it vibrating. This is resonance.