Science Grade 8 Quarter 1 Module 1 PDF

Science Quarter 1- Module 1 Week 1, Law of Inertia and Law of Acceleration Science - Grade 8 Alternative Delivery Mode Quarter 1 - Module 1: Newton’s First and Second Laws of Motion Revised Copy 2021 Republic Act 8293, section 176 states that: No copyright shall subsist in any w...

Science Quarter 1- Module 1 Week 1, Law of Inertia and Law of Acceleration Science - Grade 8 Alternative Delivery Mode Quarter 1 - Module 1: Newton’s First and Second Laws of Motion Revised Copy 2021 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalty. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this book are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education – Division of Cebu City Schools Division Superintendent: Rhea Mar A. Angtud, CESO VI Development Team of the Module Writer/Compiler/s: Joy D. Labis, Master Teacher I (CCDCAGMNHS) Emarie Kathleen G. Verano Teacher I (CCDCAGMNHS) Illustrator/Layout Artist: Content Editors: Dr. Gemma A. Bendebel, Principal II. Zapatera National High School Mr. Rommel C. Villahermosa, Assisting Principal, Don Sergio Osmena MNHS Language Editor: Mrs. Nenita Nacional, School Principal, Pardo Elementary Extension Management Team: Dr. Rhea Mar A. Angtud, Schools Division Superintendent Dr. Bernadette A. Susvilla, Assistant Schools Division Superintendent Mrs. Grecia F. Bataluna, CID Chief Mrs. Raylene S. Manawatao, EPS-Science Mrs. Vanessa L. Harayo, EPS LRMDS Printed in the Philippines by : Department of Education – Division of Cebu City, RO7 Office Address: New Imus Avenue, Barangay Day-as, Cebu City Telephone Nos.: (032)2551516 E-mail Address: [email protected] ii  This will give you an idea of the skills or What I Need to Know competencies you are expected to learn in the module. This part includes an activity that aims to check what you already know about the lesson to take. If What I Know you get all the answers correct (100%), you may decide to skip this module. This is a brief drill or review to help you link the What’s In current lesson with the previous one. In this portion, the new lesson will be introduced to What’s New you in various ways; a story, a song, a poem, a problem opener, an activity or a situation. This section provides a brief discussion of the What is It lesson. This aims to help you discover and understand new concepts and skills. This comprises activities for independent practice What’s More to solidify your understanding and skills of the topic. You may check the answers to the exercises using the Answer Key at the end of the module. This includes questions or blank What I Have Learned sentence/paragraph to be filled in to process what you learned from the lesson. This section provides an activity which will help What I Can Do you transfer your new knowledge or skill into real life situations or concerns. This is a task which aims to evaluate your level of Assessment mastery in achieving the learning competency. In this portion, another activity will be given to you Additional Activities to enrich your knowledge or skill of the lesson learned. This contains answers to all activities in the Answer Key module. At the end of this module you will also find: References This is a list of all sources used in developing this module. 1 EXPECTED SKILLS: To do well in this module, you need to remember and do the following:  Perform conscientiously all the tasks as instructed in every part.  Collaborate with other online students or consult other references, as often as needed.  Explore deeper and further as your time permits.  Take down some notes which you find important and interesting. Writing on paper or typing on your computer helps you remember and understand things easier. Plus, these may come in handy when you need to review.  Keep a journal of your insights as well as questions.  Determine the learning style and environment where you learn best so as to maximize your learning. Schedule your time for study and relaxation.  Lastly, enjoy what you are doing and be inspired to study well. The following are some reminders in using this module: 1. Use the module with care. Do not put unnecessary mark/s on any part of the module. Use a separate sheet of paper in answering the exercises. 2. Don’t forget to answer What I Know before moving on to the other activities included in the module. 3. Read the instruction carefully before doing each task. 4. Observe honesty and integrity in doing the tasks and checking your answers. 5. Finish the task at hand before proceeding to the next. 6. Submit the accomplished module every end of the week. 7. Upon submission claim the module for the following week. If you encounter any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator through text, phone call, chat, online classroom during the virtual orientation with students. Always bear in mind that you are not alone. We hope that through this material, you will experience meaningful learning and gain deep understanding of the relevant competencies. You can do it! 2  Lesson Newton’s Laws of Motion Quarter : First Quarter Content Standard : The learners demonstrate understanding Newtons three laws of motion. Performance Standard : The learners should be able to develop a written plan and implement a “Newton’s Olympics” Competency : The learners should be able to investigate the relationship between the amount of force applied and the mass of the object to the amount of change of the object’s motion. (S8FE-Ia-15) Duration : Week 1 Topic : Newton’s Laws of Motion: Law of Inertia and Law of Acceleration What I Need to Know Have you ever wondered what makes the animals move the way they do? Why do some things move faster than the others? When we ride a car why do we have to use seatbelts or wear helmets in riding motorcycles? Do we really understand why we are asked to do such? Motion has been a very familiar and common concept to all even before one has learned to walk. But is our knowledge of the concept enough for us to understand the different kinds of motion that is happening around us? In this lesson, you will know the laws governing motion which are known as, Newton’s Laws of Motion. Objectives: 1. Explain Newton’s first law of motion: Law of Inertia 2. Demonstrate Newton’s first law of motion. 3. Appreciate the concept of Law of Inertia in real life situation 4. Explain Newton’s second law of motion: Law of Acceleration. 5. Solve word problems related to the Law of Acceleration 6. Practice critical thinking skill in analyzing word problems related to the Law of Acceleration. 3  What I Know DIRECTIONS: Write the letters of your answers on a separate sheet of paper. 1. What is the measure of an object’s inertia? A. acceleration B. interaction C. mass D. net force 2. Which of the following Laws of Motion BEST explains why light objects move faster than heavy objects when equal force is applied? B. Law of Inertia B. Law of Interaction C. Law of Acceleration D. Law of Resistance 3. What makes an object placed on top of the table at rest? A. There are no forces acting on the object. B. The forces are balanced with zero net force. C There is friction between the object and the table. D. The unbalanced force is not enough to move the object. 4. When moving at the same speed, which vehicle could LESS likely do harm to a tree when it crashes into it? A. bicycle B. bus C. motorcycle D. taxi 5. Which of the following may DECREASE the acceleration of a jeepney? A. unloading passengers C. adding loads B. using powerful engines D. stepping hard on the accelerator 6. What relationship exists between mass and acceleration? A. direct B. inverse C. direct square D. inverse square 7.What causes an object to accelerate? A. acceleration B. inertia C. mass D. net force 8. Which statement is NOT TRUE about inertia? It. A. increases as the mass increases C. is the object’s property to resist motion B. decreases as the mass increases D. is present in objects, whether at rest or in motion 9. Which of these animals has the greatest inertia while at rest? A. carabao B.cat C. chicken D. pig 10. What Newton’s Law of Motion is behind the concept on the wearing of seatbelts while riding in a car? A. acceleration B. inertia C. interaction D. centripetal force 11. Which of the following is an example of exerting a force? A. a train speeding down a track C. a child running through a field B. a carpenter hammering a nail D. an airplane soaring through the sky 12. Which example identifies a change in motion that produces acceleration? A. a particle moving in a vacuum at constant velocity B. a vehicle moving down the street at a steady speed C. a ball moving at a constant speed around a circular track D. a speed skater moving at a constant speed on a straight track 13. If a force of 26 N is exerted on two balls, one with a mass of 0.52 kg and the other with a mass of 0.78 kg, which ball will have the greater acceleration? (F=ma) A. The one with a mass of.78 kg will have the greatest acceleration. B. The one with a mass of.52 kg will have the greatest acceleration. C. They will both accelerate at the same rate. D. None of the above. 14. A force of 20-N acts upon a 5-kg block. What is its acceleration? A. 4 m/s2 B. 5 m/s2 C. 10 m/s2 D. 100 m/s2 4 15. A book rests on a table. The force of gravity pulls down on the book with a force of 20 newtons. What prevents the book from accelerating downward at 9.8 m/s2? A. The table presses back up on the book with an equal and opposite force of 20 newtons. B. The table presses back up on the book with a force greater than 20 newtons. C. The table and the book together are accelerating downwards at 9.8 m/s 2. D. The inertia of the book holds it up. What’s In This lesson is all about Newton’s first and second laws of motion while the third law will be discussed in the next lesson. It is essential that we start our lesson with Newton’s laws of motion because they are the fundamental concepts of force and motion. Briefly let’s review what is force and motion. Force- any push and pull that causes change in the position of an object -anything that changes the speed, direction, or both of an object at rest or in motion which can be contact or non-contact a. Contact force-is a force that is applied by objects in contact with each other. friction -a specific type of contact force which resists motion b. Non-contact force- is a force which acts on an object without coming physically in contact with it. gravity- the force of attraction that exists among all bodies that have mass Motion- is the change of position of an object caused by unbalanced forces -can be described by the following aspects: speed, velocity and acceleration *Speed-length of distance traveled in the certain amount of time *Velocity-rate of change of displacement *Acceleration – change in the velocity of an object 5 Study the concept map below which summarizes Force and Motion. can be causes such as such as proportional to its its What is the relationship between Force and Motion? 6  What’s New Activity 1.1 INVESTIGATING INERTIA I. OBJECTIVE: To demonstrate Newton’s first law of motion. II. MATERIALS: empty glass, cardboard, 1peso coin, ruler 5-peso coins (5 pcs or more) III. PROCEDURE: Coin Drop 1. Arrange the setup as shown below. 2. Slowly pull the cardboard with your hand and observe what happens. 3. Arrange again the set-up as shown. This time, quickly flip the cardboard with your finger. Observe again what happens Science 8 Learner’s Module DIRECTIONS: Write your answers on a separate sheet of paper a. What happens when you slowly pulled the cardboard? Explain. ___________________ b. What happens when you flipped the cardboard? Explain. ________________________ Stack of Coins 4. Stack the coins on a flat level surface. 5. Quickly hit the coin at the bottom with the edge of the ruler. c. What happens when you hit the coin at the bottom? Why is this so?________________ Activity 1.2 BUS vs. CAR DIRECTIONS: When a bus collides head on with a car, which vehicle would undergo a greater change in its motion? Why? Write your prediction and explanation. Write your answer on a separate sheet of paper. study.com Prediction: _________________________________________________ Explanation: _______________________________________________ 7  What is It Have you ever wondered why our body tends to move forward when the vehicle we are riding suddenly stops or why is it easier to push an empty shopping cart than a full one? Then you must know the laws of motion which can explain why such things happen. Let’s begin by knowing the man who formulated the laws of motion, Sir Isaac Newton. Sir Isaac Newton was a physicist and one of the most influential scientists of all times. His three laws of motion became the basis for mechanics, the science of how and why objects move. These laws describe the forces acting upon an object and its motion in response to these forces. Newton combined his ideas and of the other scientists like Galileo to give us a more unified picture of how our universe works. Also, through his three laws of motion, we can describe and predict the movement of things around us. So, let’s dig deeper into the laws of motion, focusing on the first law which is the Law of Inertia and the second law, Law of Acceleration since the third law will be discussed in the next lesson. Newton's First Law of Motion (Law of Inertia) An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues to move with the same velocity unless acted on by an unbalanced force. * Activity 1.1 “Investigating Inertia”, demonstrates the first law of motion and describes how this law is shown in real life situation. independent from external force. *What is the relationship between an object's mass and its inertia? An object that has more mass will have more inertia or resistance to a change in motion. For example, let’s compare the inertia of a carabao and a chicken. If both animals are in a separate cart at rest, you would think that it would take much more effort to push the cart with the carabao in it to make the cart move, than the cart with the chicken in it. This is because the carabao has more mass than a chicken and therefore, more inertia to resist movements when it is at rest. *The second part of Newton's First Law of Motion. (An object in motion continues to move with the same velocity unless acted on by an unbalanced force.) The second part of Newton's First Law of Motion states that an object that is moving at a constant velocity, meaning the same speed and in the same direction, will continue to move at this same velocity unless an unbalanced force acts on the object. 8 *What is Inertia? Inertia is an inherent property of an object to resist change, and it is *An unbalanced force can cause an object at rest to move. If a science book is on a table and is not moving, the force of my hand lifting it up will provide the unbalanced force needed to move it. Newton’s Second Law of Motion (Law of Acceleration) The acceleration of an object is directly proportional to the net force on it and inversely proportional to its mass. * This law can be summarized in the equation: F=ma (force is the product of mass and acceleration) where: F- force m-mass a-acceleration Mass (m) is the measure of the amount of matter in an object Acceleration (a) is the rate of change of velocity per unit of time. * The acceleration of an object is equal to the sum of the forces acting on it, divided by the mass of the object a= F / m *1 Newton is the amount of force that will accelerate a 1Kg mass at the rate of 1 m/sec/sec F=ma, so 1N=1kg. m/ s² *Weight is the force due to gravity, so W =mg where: W-weight m-mass g-gravity= 9.8 m/ s² *Sample problems using the formula for the Law of Acceleration 1. The car has an acceleration of 7 m/s2 and a mass of 80.5 kg. What is the amount of the force? Given: acceleration = 7 m/s2 , mass = 80.5 kg Asked: What is the amount of the force? Force =F Formula: F= ma Solution: F = (80.5 kg) (7 m/s/s) Answer: F= 563.5 N 9  2. A car is pulled with a force of 10,500 Newtons. The car's acceleration rate is 2 m/ s². What is the mass of the car? Given: 10,500 Newtons= force, 2 m/ s²= acceleration Asked: What is the mass of the car? Mass= m Formula: m= F/A Solution: m= 10,500 N/ 2 m/ s² Answer: m= 5,250 kg 3. An unbalanced force of 48 Newtons is applied to an object with a mass of 12 kg. What is its acceleration rate? Given: 48 Newtons= force, 12 kg=mass Asked: What is its acceleration rate? Acceleration=a Formula: a= F/m Solution: a= 48 N/ 12 kg Answer: a= 4 m/ s² What I Have Learned Activity 2.1 Problem Solving (F=ma) DIRECTIONS: Solve the following problems using the formula of Newton’s second law of motion. Show your (Given, Asked, Formula, Solution, Answer) on a separate sheet of paper. 1. A skateboard has a mass of 2 kg and accelerates at a rate of 6 m/s². What is the amount of unbalanced force? 2. A truck is pulled with a force of 20 500 Newtons. The truck's acceleration rate is 4 m/ s². What is the mass of the car? 3. If a 70 kg swimmer pushes off a wall with a force of 350N, at what rate will the swimmer accelerate from the wall? Activity 2.2 DIRECTIONS: Based on your learnings about the 1 st and 2nd Laws of Motion, fill in the blanks with words/ phrases to give a complete the statements. Write your answers on a separate sheet of paper. I. NEWTON’S FIRST LAW OF MOTION 1. Newton’s first law of motion is also known as the LAW OF (a). The first law of motion says that an object that IS NOT MOVING, or is at (b) will stay at (c) and an object that IS MOVING will keep moving with constant (d) which means at the same(e) and in the same (f) UNLESS an (g) force acts on that object. 2. Inertia is defined as. 3. is property of an object which determines how much inertia it has. 4. A bowling ball has inertia than a tennis ball. 5. When riding in a moving car and the driver suddenly steps on the brake, our body will tend to move. 10  II. NEWTON’S SECOND LAW OF MOTION 6. Newton’s second law of motion is also known as the LAW OF (a).. It says that when a/an (b) force is applied to a (c) , it causes it to (d). 7.The greater the force applied, the _________ is the acceleration. 8.The lesser the force that is applied, the ____________is the acceleration. 9. Given the same amount of force applied to two objects of different masses, the one with the greater mass will have (a) acceleration while the object with the lesser mass will have (b) acceleration. 10.The equation F=ma is used to solve problems involving the second law of motion. A. What does each variable mean? F = (a) m = (b) a = (c) B. What standard unit of measurement must be used with each variable? F = (a) m = (b) a = (c) What I Can Do DIRECTIONS: Illustrate one real-life situation where each Law of motion can be applied. Give a brief description of your drawing. Write your answer on a separate sheet of paper. LAW OF INERTIA LAW OF ACCELERATION Assessment DIRECTIONS: Write the letters of your answers on a separate sheet of paper. 1. An object with a mass of 5.0 kg accelerates 8.0 m/s2 when an unknown force is applied to it. What is the amount of force? A..0625 kg/m/s B..0625 N C. 40 Kg/m/s D. 40 N 2. What is the force of a 20kg bike that accelerates at 10m/s2? A. 10 N B.20N C. 25 N D. 200N 3. How does friction affect speed? A. more friction decreases speed C. more friction increases speed B. less friction decreases speed D. less friction doesn't affect speed 4. What is Newtons 1st law of motion? A. law of gravity B. Force= Mass multiplied by acceleration C. For every action there is an equal and opposite re-action. D. An object at rest stays at rest unless acted on an unbalanced force. (inertia) 11 5. Which of the following is an example of friction that is helpful? A. Brakes used on a bike C. Tread on the bottom of your shoes B. Tires from a car on the road D. All are examples that are helpful 6. What does friction produce? A. gravity B. heat C. light D. sound 7. What is the amount of force required to accelerate a 30kg object to 10m/s 2? A. 3N B. 30 N C. 300 N D. 300m/s 8. What is the acceleration of a 48 kg object pushed with a force of 500 newtons? A. 8.78 m/s2 B. -8.78 m/s2 C. 10.41 m/s2 D. 10.42 m/s2 9. Which of the following statements about contact forces is FALSE? A. Friction is a contact force. B. Gravity is a type of contact force. C. There is more friction when rough surfaces touch. D. Contact forces require two or more surfaces to touch one another. 10. Which of the following statements about noncontact forces is FALSE? A. Noncontact forces cannot be found in nature. B. Noncontact forces are fundamental forces in nature. C. Electromagnetic force is the strongest of all noncontact forces. D. The only gravitational force on Earth is Earth’s pull toward its core. 11. A truck is pulled with a force of 40 500 Newtons. The truck's acceleration rate is 8 m/ s². What is the mass of the car? A. 5,062 kg B. 5,062.5 kg C. 5,064 kg D. 5,065 kg 12. What is the mass of a cart that has an acceleration of 5 m/s/s when a net force of 2000 N is applied to it? A. 10,000 kg B. 2000 kg C. 1000 kg D. 400 kg 13. A 2,000-kg car is sitting at rest in a parking lot. A bike and rider with a total mass of 60 kg are traveling along a road at 10 km/h. Which system has more inertia? The______. A. car has more inertia, as its mass is less than the mass of the bike B. bike has more inertia, as its mass is less than the mass of the car C. car has more inertia, as its mass is greater than the mass of the bike D. bike has more inertia, as its mass is greater than the mass of the car 14. Two people push a 2,000-kg car to get it started. An acceleration of at least 5.0 m/s 2 is required to start the car. Assuming both people apply the same magnitude force, how much force will each need to apply if friction between the car and the road is 300 N? A. 4850 N B. 5150 N C. 97000 N D. 10300 N 15. What is the SI unit of force? A. Kg B. m C. N D. Kg/m 12 References https://www.vanderbilt.edu/AnS/physics/panvini/p110a/Ch2.html https://openstax.org/books/physics/pages/4-multiple-choice https://www.wsfcs.k12.nc.us/site/handlers/filedownload.ashx?moduleinstanceid=17999&dataid=218 958&FileName=Forces%20and%20Motion%20Unit%20Test.pdf https://quizizz.com/admin/quiz/57260238ad9b3f0d18340432/newtons-laws-of-motion Campo, Pia C., et.al. Science 8 Learner’s Module, First Edition. Philippines:Department of Education, 2013. Campo, Pia C., et.al. Science 8 Teacher’s Guide, First Edition. Philippines:Department of Education, 2013. Key Newton’s Laws Worksheet. Accessed July 7,2020. https//www.cusd80.com>lib Learning Module Science G8/Q1. 2017, Force, Motion and Energy.Philippines: Department of Education 2017_SciG8Q1-1 Lim, Anne Brigette U.Science for the 21 st Century Learner. Philippines. Diwa Learning Systems, Inc., 2012. Newton’s Laws Study Guide. Accessed July 14, 2020. www.yb.tl>newtons_laws_study_guide 13  14 Activity 2.2 I. NEWTON’S FIRST LAW OF MOTION 1. (a)law of inertia, (b)rest, (c)rest, (d)velocity, (e)speed, (f)distance, (g)outside 2. the resistance of any physical object to any change in its state of motion 3. mass 4. greater 5. forward. II. NEWTON’S SECOND LAW OF MOTION 6. (a) acceleration (b) unbalanced (c) mass (object), (d)accelerate. 7. greater. 8. lesser 9. (a)lesser, (b) greater 10. A. What does each of the variables mean? F = (a)FORCE m = (b)MASS a = (c)ACCELERATION B. What unit of measurement must be used with each variable? F = (a) kg. m/ s²(N – Newton) (b) m = kg (c) a = m/ s² What I have learned? Activity 2.1 1.Given : mass= 2kg, a= 6m/s2 2.Given: F=20,500 N, a= 4 m/ s² 3.Given : mass= 70kg, F= 250N Asked : Force Asked: mass Asked : acceleration Formula :F=mxa Formula: m= F/A Formula :a=F/m Solution :F=2kgx6m/s2 Solution: m= 20,500 N/ 4 m/ s² Solution : a= 250N/70kg Answer : F = 12kg/ms2 /12N Answer: m= 5,125 kg Answer : a= 3.6 m/s2 What’s New? Activity 1.1 “ Investigating Inertia” Answers to Questions Coin Drop a.When we slowly pulled the cardboard, the coin on top moved with the cardboard. The frictional force between the coin and the cardboard had caused the coin to stay on top of the cardboard and move with it. b.When we flicked the cardboard with our finger, the cardboard moved forward but this time, the coin did not move with it. So when the cardboard was removed from underneath the coin, the coin dropped into the glass. The coin did not move forward with the coin because of its inertia. Stack of Coins c.When we hit the bottom coin with the edge of the ruler, the coin moved out from the pile but the other coins stayed in place. The inertia of the other coins has caused them to stay in place or not to move out with the coin that was hit by the ruler. Answer key OUTSIDE BACK COVER) For inquiries or feedback, please write or call: Printed in the Philippines by: Department of Education – Division of Cebu City Office Address : New Imus Avenue, Barangay Day-as, Cebu City Telephone Nos. : (032) 2551516 E-mail Address : [email protected] 15 16 17 18 19 20 21