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Benchmark Pop Quiz

Learn about the properties of waves, including wavelength, amplitude, and frequency, and understand how energy transforms between potential and kinetic forms. Explore different types of waves such as sound and light waves.

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Benchmark Pop Quiz

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  1. Benchmark Pop Quiz 13, 15, 21, 23, 29 Turn in today! Turn in DOS also! Monday – Objective #4 18, 27, 44, 46

  2. TAKE NOTES! Wave • A wave is any disturbance that transmits energy through matter or space.

  3. TAKE NOTES! Medium • All mechanical waves require a medium through which to travel. • The medium is the material through which mechanical waves travel. • This type of wave transfers energy by the vibration of particles in a medium. One particle vibrates and then passes its energy to a particle next to it. So on and so forth. • energy is transported throughout the medium, without the transport of any matter.

  4. WAVE PROPERTIES WAVELENGTH TAKE NOTES! CREST AMPLITUDE REST POSITION TROUGH FREQUENCY CREST – highest point of a wave TROUGH – lowest point of a wave WAVELENGTH – distance from peak to peak AMPLITUDE – the distance a wave rises/falls from its rest position FREQUENCY – the number of waves passing a given point HERTZ - how many waves goes by per second

  5. Frequency and Wavelength Longer wavelengths Larger frequencies result in smaller result in shorter frequencies. wavelengths. As the frequency of a wave increases, its wavelength decreases. Frequency and wavelength are related! TAKE NOTES!

  6. Sound Waves Water Waves Types of Mechanical Waves Seismic Waves

  7. TAKE NOTES! SOUND • Sound is a mechanical wave that travels through air at about 340 m/s or 1100 ft. per second. • Loud sound waves are greater amplitudes than soft sound waves. • Loud sounds carry more energy than soft sounds. • Sound travels faster in a solid than a liquid, and faster in a liquid than a gas. • In a sound wave, either the wavelength or frequency determines the pitch. • Pitch is the high or low of a sound. • Sound level (loudness) is measured in units called decibels. • Vocal cords produce sound by vibration. • As the frequency of a sound wave increases, its wavelength decreases.

  8. Then there are light waves that requirenomedium at all. They are called electromagnetic waves

  9. TAKE NOTES! LIGHT • Light is a electromagnetic wave thattravels through air at about 300,000 km/s. • Bright lights have greater amplitudes (more energy) than the waves that make up dim light. • Because frequency and wavelength are related, either the wavelength or frequency of a light wave determines the color of the light. Blue light has a larger frequency and shorter wavelength than red light. Red light has a shorter frequency and a longer wavelength. • Light travels through faster in gases than in solids or liquids. Example: speed of light is one and a half times faster in air than it is in glass.

  10. Review • Waves are the way energy is transferred. • Waves that travel through a medium are called mechanical waves and can be water waves, sound waves, or earthquakes (seismic waves) • Waves that do not travel through a medium are called electromagnetic waves, such as light, radio waves, and X-rays.

  11. EXAMPLE 2 When a student rides a bike down a hill, potential energy is transferred into kinetic energy. Potential Energy Kinetic Energy

  12. KEY TERMS • An energy transformation occurs when energy changes from one form to another. • Energy transformations occur in energy production (as in conversions of energy for use in everyday life). • Potential Energy is the energy that is stored because of an object’s position. • The energy of an object due to its motion is called Kinetic Energy. TAKE NOTES!

  13. Forms of Energy

  14. TAKE NOTES! Energy is the ability to cause change

  15. What is Energy? • An exertion of force • The ability to do work • Potential(stored) and Kinetic(motion) a separate division of each type of energy

  16. TAKE NOTES! POTENTIAL ENERGY Energy an object has because of its position

  17. TAKE NOTES! KINETIC ENERGY • Energy of motion. Only a moving object has kinetic energy • Amount of energy depends on speed and mass

  18. EXAMPLE 1 POSITION 1 Potential Energy The boulder at the top of the hill has potential energy and no kinetic energy. POSITION 2 Kinetic Energy Potential Energy As the boulder rolls down the hill, the potential energy transforms into kinetic energy and kinetic energy becomes greater until POSITION 3 The boulder is in a resting position with low potential energy and no kinetic energy.

  19. TAKE NOTES! The amount of kinetic energy also depends on the mass and the speed of an object. Kinetic energy increases as speed increases. The faster an object moves, the more kinetic energy it has. EXAMPLE 3: The faster a bowling ball moves, the harder it will strike the pins, the more pins it can knock down.

  20. As the ball leaves the ground, it is moving the fastest and has the maximum kinetic energy. As the ball moves upward, it slows down as it’s kinetic energy is transformed into potential energy. As the ball moves downward, it speeds up as its potential energy is transformed into kinetic energy. 2 EXAMPLE 4 Explain how energy is transformed as the ball rises and falls. 3 1

  21. TAKE NOTES! Energy vs. Matter everything on Earth is either energy or matter • Matter has mass • and weight • Matter takes up • space • Matter is NOT • energy • Energy has no mass or weight • Energy does not take up space • Energy is NOT matter CONSERVATION of ENERGY – energy can not be created or destroyed

  22. FORMS OF ENERGY R E C T M N • Radiant – infrared/absorbed • Electrical - power • Chemical - chemicals • Thermal - heat • Mechanical – motion • Nuclear – atoms nuclei TAKE NOTES!

  23. TAKE NOTES! RADIANT ENERGY Energy carried by light and electromagnetic waves is called radiant energy. Light energy travels at a speed of 300,000 km/s.

  24. TAKE NOTES! ELECTRICAL ENERGY energy of electrons moving along a path (electrical current/charges)

  25. TAKE NOTES! CHEMICAL ENERGY energy stored in chemical bonds (when chemicals are broken apart and new molecules are formed, energy is released)

  26. Each of these items contains chemical energy.

  27. TAKE NOTES! THERMAL ENERGY energy due to molecular movement within an object increased temperature = increased thermal energy related to temperature of substance

  28. MECHANICAL ENERGY Energy created by motion or position.

  29. TAKE NOTES! NUCLEAR ENERGY energy stored in the nucleus of an atom

  30. The thermal energy given off by the nuclear reaction can be used to heat water to power an electric power plant.

  31. Examples of Energy Transformations Your body converts chemical energy in food into energy …. it needs to move,think,grow and heat the body.

  32. Examples of Energy Transformations An electric current that flows in a wire carries electrical energy that can be used in many ways. A stove transforms electrical energy to heat energy that boils the water and cooks food. A light bulb converts electrical energy into light energy when you flip a switch.

  33. Examples of Energy Transformations The most common windmills convert the kinetic energyof the wind into rotary motion of the generator. The rotating generator, typically a direct-drive permanent magnet alternator, produces electricity. The chemical fuel is transformed into thermal and mechanical energy needed to run the car.

  34. QUESTION The boulder would have the greatest kinetic energy at which of the positions on the waterfall? A position 1 B position 2 C position 3 D position 4 1 A 4 2 3 B B position 2

  35. A yo-yo can demonstrate both Potential and Kinetic energy. When does a yo-yo have it greatest potential energy? A In the hand before the yo-yo is releasedB At the bottom of the stringC When the yo-yo is fallingD When the yo-yo is climbing the string A In the hand before the yo-yo is released.

  36. Which will have the most kinetic energy rolling down the hill? A TruckB BallC RunnerD All of the are examples of Potential energy. Answer: A

  37. Which of the following can be used to transform chemical energy into heat energy? A. melting a candle Answer: B B. lighting a match C. solar panels D. a light bulb

  38. Which of these types of energy conversions occurs in a battery-powered flashlight? A. Thermal to mechanical B. Light to electrical C.Thermal to chemical D. Chemical to electrical Answer: D

  39. Windmill farms are becoming a popular method of generating electricity for some communities. What form of energy in wind is used to turn the giant blades of the windmill? • Chemical • Mechanical • Electrical • Thermal The correct answer is B, Mechanical Energy. Wind, which turns the windmill blades, is the movement of air particles.

  40. In a nuclear reactor, the energy used to turn water into steam is in what form? A. Chemical B. Nuclear C. Electrical D. Thermal The correct answer is “D”, thermal energy. The nucleus of the uranium atom contains nuclear energy, but this is converted into thermal energy when the nucleus is split. The thermal energy is then used to heat the water to the boiling point.

  41. Nutrients entering muscle cells in the body are converted into heat. What form of energy is stored in the nutrients? A. Chemical B. Nuclear C. Electrical D. Thermal The correct answer is “A”, chemical energy. Chemical energy is stored in the chemical bonds of the food molecules.

  42. RADIATIONwarms the surface. The air near Earth’s surface is heated by CONDUCTION. Cooler air pushes warm air upward, creating a CONVECTION CURRENTS. Transfer of HEAT within Earth’s atmosphere.

  43. Methods of Heat Transfer - Energy • Radiation – (rays) • 30% of the Sun’s rays are reflected back into space • Transfer of electromagnetic waves • Transfer of heat energy to an object of lower temperature. • Ozone layer absorbs ultraviolet radiation • Is reflected by clouds, surfaces and the atmosphere. • Conduction (touch) • Is the transfer of energy by fast moving molecules to cooler • molecules - to same temperature. • Convection (currents) • Caused by density differences in the air.

  44. Simple Machines • Lever • Inclined plane • Wheel and axle • Pulley • Wedge • Screw

  45. TAKE NOTES! Machines Can… • Make work EASIER to accomplish (but amount is the same) • Change magnitude of force required to accomplish task • Change direction of force required to accomplish task

  46. TAKE NOTES! Machines Cannot… • Decrease the amount of work necessary to accomplish a given task • Have 100% efficiency • Run perpetually

  47. TAKE NOTES! Simple Machines Levers – is an arm/bar that pivots on a fulcrum Inclined Plane - a ramp, only one that does not move

  48. TAKE NOTES! Simple Machines Wheel and Axle – transfer of energy through the axle to the wheel Pulley – a wheel with a rope wrapped around it on a fixed axle

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