Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Physical Science 2nd Semester Study Guide with Answers Energy and Energy Transformations 1. Explain transfer of heat through Conduction, Convection and Radiation. Include examples and diagrams. Conduction-direct contact through solids, convection-heat is transferred through liquids and gases through currents. Radiation – when energy is transferred by electromagnetic waves through empty space. (See text chapter 15 section 2 for examples & diagrams) 2. Explain how potential can change to kinetic energy and vice versa. Potential energy is stored energy and when an object begins to move it is converted to kinetic energy. 3. Give examples of kinetic energy anything in motion, ball in motion, airplane flying. Kinetic E is based on mass and speed. 4. Give examples of potential energy any object that has the ability to have motion but is not in use yet. Potential E is based height and mass. 5. How do currents of heat travel in a liquid or gas? Convection 6. What form of energy does a vibrating object give off? Sound 7. Describe the energy transformations that occur when lighting a match Mechanical E.(moving hand), chemical (chemical reaction), thermal (heat), and then radiant (light from match lighting) 8. The law of conservation of energy states: Energy can’t be created or destroyed but it only changes forms. 9. Draw and label a diagram illustrating the greatest potential/kinetic energy. Think of a roller coaster and the greatest potential is at its highest point and the greatest kinetic is right before it reaches its lowest point. 10. What process does heat transfer in a vacuum? Radiation-it can occur in a vacuum because a vacuum is where there are no particles of matter and radiation occurs in waves around matter not through it like in conduction and convection. 11. What are two ways that heat can be transferred by collisions of particles in matter? Conduction-direct contact through solids, convection-heat is transferred through liquids and gases through currents 12. Describe what happens when chemical energy is converted into thermal energy. This happens with a chemical reaction and the amount of energy stays the same it just changes form-Law of conservation of energy. 13. Compare one glass of water at 0 C degrees and one glass of water at 30 C degrees. Heat always transfers from hot to cold. There is more thermal energy and kinetic energy the warmer the water. 14. What can cause convection in liquids and gases? When you heat a liquid from below it causes currents because heat rises then cools slightly and the process repeats itself. Forces, Motion & Simple Machines 15. What causes an object to slow down when initially moving? Friction because it opposes the motion of an object 16. Which simple machine would you use to pry a heavy rock from the ground? Lever-any bar that has a pivot point (fulcrum) and is used to do work 17. Explain how mass controls acceleration of an object. Acceleration is based on mass and the amount of force. If the mass of an object is less, then it requires less force. However, if the mass of 2 metal balls is 15 grams and 2 grams and equal force is applied then the 2 gram ball will accelerate faster. 18. How does a wheel and axle make work easier? Increases effort force and increases the distance covered 19. If the threads of a screw where unwrapped what would they represent? Incline plane 20. Which kinds of forces are exerted on an object if there is a net force of zero? Balanced because each force being exerted is equal to the other. When you subtract all forces from each other that should equal zero. 21. How do you calculate net force? Subtract 22. Describe 3 ways an object accelerates. An object is considered accelerating when it speeds up, slows down or changing direction like turning. 23. How does a single fixed pulley make work easier? Changes the direction of the input force 24. An ice skater is moving in a straight line with constant speed. Which describes the forces acting on the skater? The forces are balanced because nothing is changing, not the speed or direction. 25. What can cause a machine to be less than 100 percent efficient?Friction 26. What is the difference between speed and velocity? Velocity has direction 27. How do you calculate work? Work divided by time 28. Explain how a lever works and include examples. A lever is a bar that pivots around a fixed point called a fulcrum. 1st class – scissors & pliers; 2nd class – wheelbarrow; 3rd class – baseball bat 29. Explain how momentum is transferred when bowling.When the bowling ball hits the pins, the ball and the binse bounce off each other. The momentum of the ball and the pins changes during the collison. The law of conservation of momentum means that collisions between these objects don’t change the total momentum of all the objects in the group. 30. Based on Newton’s 1st Law (state), what happens to an object that is moving and is suddenly stopped? Newton’s first law states that objects in motion tent to stay in motion and objects at rest tend to stay at rest unless acted upon by an outside force. If a car is moving and suddenly stops, the car stops but the person inside will still move forward until the seatbelt stops them. (momentum) Sound/Light Waves 31. Draw and label a diagram of parts of a transverse and compressional wave. In text p. 467 & 468 32. List types of electromagnetic waves (remember your flipbook) Lowest to Highest frequency. Remember the Gamma Rays has the strongest energy and the shortest wavelength and the highest frequency. Radio waves have the opposite on each. Remember ROYGBIV-red being longest wavelength and violet being the shortest. Order – Saying “Red Martians Invade Venus Using X-Ray Guns” 33. Describe what happens when refraction occurs. The light wave actually changes speed as it goes from one medium to another. An example is like when we put the pencil in the water and the pencil appeared bent or broken. 34. What travels faster? Sound or light, why? Light travels the fastest. Think about this is why you see the lightning and then hear the thunder. 35. What reflects light? All matter reflects light 36. How do you measure wavelength? Crest to crest, Trough to trough, or from any given point on a wave to the same point on the next wave. For a sound wave, from the center point of a compression or rarefaction to the center of the next compression or rarefaction. 37. Which color is the best to wear when hot? Light colored reflects light and heat. 38. Where can sound not travel? In empty space or a vacuum. 39. Explain the Doppler Effect and include a diagram representing the waves. (see text p. 496) As an object moves closer to you the frequency increases which creates a higher pitch, and as it moves away from you the frequency decreases which creates a lower pitch. 40. Explain how sound waves transfer. Where do they travel the fastest, slowest? Sound travels by vibrating particles. It travels fastest in a solid and slowest in a gas. 41. What would make a pitch of a sound wave lower? By decreasing the frequency or increasing the length of a wave. A pitch can also be lowered with a string instrument by increasing the thickness of the string or decease the tension of the string. 42. What type of image does a flat mirror produce? A regular, because light is reflecting back at the same angle 43. What part of the eye is responsible for controlling the amount of light that enters? The pupil opens more when more light is needed and constricts when less light is to see 44. What happens to the particles in a medium when sounds pass through it? They vibrate 45. How is wave speed calculated? Wavelength x frequency 46. What would you measure to determine a wave’s frequency? The number of waves that pass a given point in a second 47. A lightning flash produces thunder at the same time the lightning flash occurs. What is the best way to explain why we see the lightning before we hear the thunder? Light waves travel faster than sound waves. 48. Explain how light travels through matter and what happens when no matter is present, vacuum. In a vacuum where no particles are present because light has to travel around matter so it travels faster. 49. What describes why a certain flower has a red color? Red light is being reflected and all other colors are being absorbed. 50. Draw and label: concave lens, convex lens, concave mirror, convex mirror-how does light behave with each? Remember a difference between a lens and a mirror is the lens allows light waves to pass through it. Concave is angled like a cave when you are walking into it. The image flipped and with convex the angle becomes larger at the edges. 51. What do waves carry as they move from one place to another? Waves carry energy as they move. 52. What is frequency measured in? The unit of measurement for frequency is hertz. 53. Describe all factors involved with the amplitude of a sound wave. Amplitude represents the energy of a wave, the height of a wave and the sound intensity of a sound wave. 54. Why does refraction of a wave occur when the wave travels from one material into another? The wave speed changes because density of the particles is different from one particle to another. With sound waves the wave speed increases when the particles are closer together and with light, the wave speed slows down because the particles are close together. 55. What EM waves do all warm bodies emit? Heat as infrared waves 56. Explain how light behaves with each: transmitting, reflecting, refracting, diffracting. Transmitting means the light wave passes through a medium; reflecting means the light wave will bounce back at you after hitting a barrier; refracting is the bending of light wave as it passes at an angle from one medium to another, and diffracting is the bending, spreading or interference of light waves when they go through a narrow opening. 57. Compare transparent, translucent and opaque transfer of light. Transparent means the light is allowed to pass through a material, translucent means that some light will pass through the material but also scatter the light in all directions. Opaque means light will not be allowed to pass through the material. Electricity 58. Describe how electric charges exert forces on each other? Like charges will repel and unlike charges will attract. The electric force between two charged objects gets stronger as the charges get closer. Also, the amount of charge on each will have an effect on the force. 59. In a series circuit, what is the same for every device in the circuit? The flow of electricity 60. What happens in a series circuit if one of the light bulbs is unscrewed? None of the light bulbs will be lit. 61. What device helps make an electromagnet work? Discussion –Know enough to write a paragraph for each. Diagrams with labels should be included. 1. Why do we see the color of red when looking at an apple? 2. Jesse and Heather were wading at the shoreline. They both realized that the shapes of the objects they saw on the bottom appeared distorted. Why would the objects appear this way? 3. Explain the advantages and disadvantages of series and parallel circuits in terms of how much energy flows to each bulb, whether lights stay lighted when a circuit fails and draw a picture and label each. 4. The advantage of a simple machine is that it makes doing a job easier. Describe and give an example of the three ways that simple machines can make doing a job easier. 5. State the law of conservation of energy and explain how it is applied through an example during its transformation. 6. Explain the 3 ways to make an electromagnet stronger.