Types of Interactions Chapter Questions Transfer of Forces 1. Forces are pushes/pulls of an object. Explain at least 4 forces that we observe in nature. 2. How are forces transferred without 2 objects being in contact? 3. When an unbalanced force acts on an object, what affect does this have on the object? 4. In your own words, differentiate between forces acting via direct contact and forces exerted via fields. 5. Define the term Field of Force as it applies to the area of physics. 6. List 2 types of forces that act through the use of a field. Law of Gravitation 7. Write a statement that summarizes Newton s Universal Law of Gravitation. 8. What is meant by the term Universal Law? 9. What two factors affect the force of gravitation acting between two objects? 10. What is the mathematical relationship between an object s mass, and the force of gravitation exerted by that mass? 11. What happens to the force of gravitation as distance away from the object is increased? 12. Sketch a graph of Force of Gravitation (N) vs. Mass (kg) between any two objects. 13. Sketch a graph of Force of Gravitation (N) vs. Distance of Separation (m) between any two objects. 14. In your own terms, explain why we can t feel the force of gravitation exerted by objects such as people. 15. Draw a sketch of the gravitational field surrounding an object such as the Earth, and explain why the field lines diverge (spread out) as we move away from the surface of the planet. 16. Explain why the field lines point inward toward a mass when we draw a gravitational field line diagram around an object such as planet Earth.
17. Explain why the force of gravitation for Jupiter is greater than the Force of gravitation for the Moon. 18. If the Earth mass doubled, your weight would? Explain. 19. If the Earth s radius doubled, your weight would? Explain. Interactions between Electric Charges 20. Define electric charge and list the two types of charge. 21. What are the 3 particles that give matter electrical charge? List the charge of each particle. 22. Explain the balance of electrons and protons in a neutral object. 23. Explain the balance of charge in a negatively charged object. 24. Explain the balance of charge in a positively charged object. 25. A charged balloon has a mixture of charge including +100 C and -200 C. What is the overall charge of the balloon? 26. Who was the person who first used the terms positive and negative when referring to electricity? 27. Define Electric charge Forces between Charges 28. What is static cling? 29. Define Coulomb s Law. 30. What type of force acts between like charges? 31. What type of force acts between unlike charges? 32. What type of force acts between neutrally charged particles? 33. As charge increases, what is the effect on the force between those charges? 34. As charge decreases, what happens to the force between two objects? 35. Sketch a graph of Electric Force (N) vs. Distance of Separation (m) between any two charged
objects. 36. Differentiate between Newton s Law of Gravitation and Coulomb s Law. Draw a Venn Diagram to show their similarities and their differences. Electric Fields 37. Draw the field lines that exist between two unlike charges. 38. Write the rules for drawing electric field lines. 39. Draw the field that exists between 2 oppositely charged parallel plates. Explain the field that exists between these 2 objects 40. What is the electric field around a neutrally charged object? Magnetism 41. What is magnetism? 42. Explain William Gilbert s idea about the Earth. 43. What is a magnetic domain? 44. Compare the orientation of magnetic domains in a)magnetized substances, and b) unmagnetized substances. 45. Compare/Contrast a Temporary Magnet and a Permanent magnet. 46. What are the 3 ferromagnetic substances? 47. Draw a sketch/label a basic electromagnet. 48. What happens to the magnetism produced by an electromagnet when the electrical current is removed? Magnetic Fields 49. Sketch the magnetic field around a simple bar magnet. 50. List the 3 basic rules for magnetic field lines. 51. Explain the forces exerted between a) like magnetic poles, and b) unlike magnetic poles.
52. Compare the field shapes between like charges vs. like magnetic poles. Why do they look the same? 53. Why does the south pole of a bar magnet point at the Earth s South geographic pole? Electromagnetic Interactions 54. Describe the contributions of Hans Christian Oersted. 55. Draw the magnetic field around a straight wire carrying a current. 56. What happens to the strength of a magnetic field around a wire when a) current is increased, and b) when we move away from the current carrying wire? 57. Describe the right hand rule. 58. Draw the magnetic field around a coil. 59. Describe the left hand rule. 60. Define induction. 61. What happens when a bar magnet is forced through a looped wire? 62. What happens when we pass the loop around a stationary bar magnet? 63. Why is the relationship between electricity and magnetism so important to society? ANSWERS
1. Gravity,Friction, electric force, magnetism, 2. Fields 3. Acceleration 4. Fields are exerted with touch through space. Other forces are produced by direct contact. 5. Field of Force A force exerted through empty space. 6. Electricity & Magnetism 7. Masses cause gravitational forces and as distance increases the force decreases. 8. Always true 9. Mass & distance of separation 10. Mass- directly proportional, distance- inversely proportional 11. Decreases 12. See presentation pg. 24 13. See presentation pg. 24 14. People have a small mass, so they exert small gravitational attraction. 15. See presentation pg. 28 16. Attraction 17. More mass 18. Double. Directly proportional 19. Reduced. Inversely proportional 20. Positive and negative 21. Protons +, electrons -, and neutrons 0 22. Equal 23. More electrons than protons 24. More protons than electrons 25. -100 26. Ben Franklin 27. Property of matter where objects feel forces near other charged objects 28. Electrical attraction 29. Forces exerted between charges. Like- repel, unlike-attract 30. Repulsion 31. Attraction 32. No force 33. Increases 34. Decreases 35. See slide 58 36. Grav only attracts Coulombs attracts and repels 37. See slide 67 38. Exit +, enter -, never cross, closer lines = stronger field 39. See slide 68 40. None
41. Property of matter that causes forces due to electricity in motion 42. Earth is a giant magnet 43. Microscopic magnetic region 44. A) magnetized- domains aligned, b) unmagnified domains randomized 45. Temporary loses magnetism permanent holds it. 46. Iron,nickel,colbalt 47. See slide 77 48. Lost 49. See slide 84 50. Exit north, enter south, never cross, closer lines = stronger field 51. Like- repel, unlike- attract 52. Similar in action and look. 53. Magnetic and geographic poles of earth are inverted. 54. Electrical current causes magnetism 55. See slide 107 56. Increase current = stronger force, increase separation = weaker force 57. See slide 111 58. See slide 113 59. See slide 114 60. Electricity causes magnetism and vice versa 61. Produces a current in the wire 62. Produces a current in the wire 63. We use it to produce power and for communication