New Jersey Center for Teaching and Learning Slide 1 / 81 Progressive Science Initiative This material is made freely available at www.njctl.org and is intended for the non-commercial use of students and teachers. These materials may not be used for any commercial purpose without the written permission of the owners. NJCTL maintains its website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional learning community, and/or provide access to course materials to parents, students and others. Click to go to website: www.njctl.org Slide 2 / 81 8th Grade Types of Interactions Classwork and Homework www.njctl.org Slide 3 / 81 Classwork #1: Transfer of Forces
1 Forces are pushes/pulls of an object. Explain at least 4 forces that we observe in nature. Slide 4 / 81 2 How are forces transferred without 2 objects being in contact? Slide 5 / 81 3 When an unbalanced force acts on an object, what affect does this have on the object? Slide 6 / 81
Slide 7 / 81 Homework: Transfer of Forces 4 In your own words, differentiate between forces acting via direct contact and forces exerted via fields. Slide 8 / 81 5 Define the term Field of Force as it applies to the area of physics. Slide 9 / 81
6 List 2 types of forces that act through the use of a field. Slide 10 / 81 Slide 11 / 81 Classwork #2: Law of Gravitation 7 Write a statement that summarizes Newton s Universal Law of Gravitation. Slide 12 / 81
8 What is meant by the term Universal Law? Slide 13 / 81 9 What two factors affect the force of gravitation acting between two objects? Slide 14 / 81 10 What is the mathematical relationship between an object s mass, and the force of gravitation exerted by that mass? Slide 15 / 81
11 What happens to the force of gravitation as distance away from the object is increased? Slide 16 / 81 12 Sketch a graph of Force of Gravitation (N) vs. Mass (kg) between any two objects. Slide 17 / 81 13 Sketch a graph of Force of Gravitation (N) vs. Distance of Separation (m) between any two objects. Slide 18 / 81
Slide 19 / 81 Homework: Law of Gravitation 14 In your own terms, explain why we can t feel the force of gravitation exerted by objects such as people. Slide 20 / 81 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. Slide 21 / 81
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. Slide 22 / 81 17 Explain why the force of gravitation for Jupiter is greater than the Force of gravitation for the Moon. Slide 23 / 81 18 If the Earth mass doubled, your weight would? Explain. Slide 24 / 81
19 If the Earth s radius doubled, your weight would? Explain. Slide 25 / 81 Slide 26 / 81 Classwork #3: Interactions between Electric Charges 20 Define electric charge and list the two types of charge. Slide 27 / 81
21 What are the 3 particles that give matter electrical charge? List the charge of each particle. Slide 28 / 81 22 Explain the balance of electrons and protons in a neutral object. Slide 29 / 81 23 Explain the balance of charge in a negatively charged object. Slide 30 / 81
Slide 31 / 81 Homework: Interactions between Electric Charges 24 Explain the balance of charge in a positively charged object. Slide 32 / 81 25 A charged balloon has a mixture of charge including +100 C and -200 C. What is the overall charge of the balloon? Slide 33 / 81
26 Who was the person who first used the terms positive and negative when referring to electricity? Slide 34 / 81 27 Define Electric charge. Slide 35 / 81 Slide 36 / 81 Classwork #4: Forces between Charges
28 What is static cling? Slide 37 / 81 29 Define Coulomb s Law. Slide 38 / 81 30 What type of force acts between like charges? Slide 39 / 81
31 What type of force acts between unlike charges? Slide 40 / 81 Slide 41 / 81 Homework: Forces between Charges 32 What type of force acts between neutrally charged particles? Slide 42 / 81
33 As charge increases, what is the effect on the force between those charges? Slide 43 / 81 34 As charge decreases, what happens to the force between two objects? Slide 44 / 81 35 Sketch a graph of Electric Force (N) vs. Distance of Separation (m) between any two charged objects. Slide 45 / 81
36 Differentiate between Newton s Law of Gravitation and Coulomb s Law. Draw a Venn Diagram to show their similarities and their differences. Slide 46 / 81 Slide 47 / 81 Classwork #5: Electric Fields 37 Draw the field lines that exist between two unlike charges. Slide 48 / 81
38 Write the rules for drawing electric field lines. Slide 49 / 81 Slide 50 / 81 Homework: Electric Fields 39 Draw the field that exists between 2 oppositely charged parallel plates. Explain the field that exists between these 2 objects Slide 51 / 81
40 What is the electric field around a neutrally charged object? Slide 52 / 81 Slide 53 / 81 Classwork #6: Magnetism 41 What is magnetism? Slide 54 / 81
42 Explain William Gilbert s idea about the Earth. Slide 55 / 81 43 What is a magnetic domain? Slide 56 / 81 44 Compare the orientation of magnetic domains in a)magnetized substances, and b) un-magnetized substances. Slide 57 / 81
Slide 58 / 81 Homework: Magnetism 45 Compare/Contrast a Temporary Magnet and a Permanent magnet. Slide 59 / 81 46 What are the 3 ferromagnetic substances? Slide 60 / 81
47 Draw a sketch/label a basic electromagnet. Slide 61 / 81 48 What happens to the magnetism produced by an electromagnet when the electrical current is removed? Slide 62 / 81 Slide 63 / 81 Classwork #7: Magnetic Fields
49 Sketch the magnetic field around a simple bar magnet. Slide 64 / 81 50 List the 3 basic rules for magnetic field lines. Slide 65 / 81 51 Explain the forces exerted between a) like magnetic poles, and b) unlike magnetic poles. Slide 66 / 81
Slide 67 / 81 Homework: Magnetic Fields 52 Compare the field shapes between like charges vs. like magnetic poles. Why do they look the same? Slide 68 / 81 53 Why does the south pole of a bar magnet point at the Earth s South geographic pole? Slide 69 / 81
Slide 70 / 81 Classwork #8: Electromagnetic Interactions 54 Describe the contributions of Hans Christian Oersted. Slide 71 / 81 55 Draw the magnetic field around a straight wire carrying a current. Slide 72 / 81
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? Slide 73 / 81 57 Describe the right hand rule. Slide 74 / 81 58 Draw the magnetic field around a coil. Slide 75 / 81
Slide 76 / 81 Homework: Electromagnetic Interactions 59 Describe the left hand rule. Slide 77 / 81 60 Define induction. Slide 78 / 81
61 What happens when a bar magnet is forced through a looped wire? Slide 79 / 81 62 What happens when we pass the loop around a stationary bar magnet? Slide 80 / 81 63 Why is the relationship between electricity and magnetism so important to society? Slide 81 / 81