Physical Science Quarter 2 - Module 6 PDF

Senior High School NOT Physical Science Quarter 2 - Module 6 Week 2: The Laws of Physics Department of Education Republic of the Philippines Physical Science-Grade 11/12 Alternative Delivery Mode Self-Lea...

Senior High School NOT Physical Science Quarter 2 - Module 6 Week 2: The Laws of Physics Department of Education Republic of the Philippines Physical Science-Grade 11/12 Alternative Delivery Mode Self-Learning Module Quarter 2 - Module 6: The Laws of Physics First Edition, 2020 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 Cagayan de Oro Schools Division Superintendent: Dr. Cherry Mae L. Limbaco, CESO V Development Team of the Module Module Developer: Noeme S. Lagos Reviewers: Illustrator and Layout Artist: Management Team Chairperson: Cherry Mae L. Limbaco, PhD, CESO V Schools Division Superintendent Co-Chairpersons: Alicia E. Anghay, PhD, CESE Asst. Schools Division Superintendent Members Lorebina C. Carrasco, OIC-CID Chief Jean S. Macasero, EPS-Science Joel D. Potane, LRMDS Manager Lanie O. Signo, Librarian II Gemma Pajayon, PDO II Printed in the Philippines by Department of Education – Bureau of Learning Resources (DepEd-BLR) Office Address: Fr. William F. Masterson Ave Upper Balulang Cagayan de Oro Telefax: (08822)855-0048 E-mail Address: [email protected]  Senior Senior High High School School Physical Science Quarter 2 - Module 6 The Laws of Physics This instructional material was collaboratively developed and reviewed by educators from public and private schools, colleges, and or/universities. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the Department of Education at action@ deped.gov.ph. We value your feedback and recommendations. Department of Education Republic of the Philippines  Table of Contents What This Module is About....................................................................................................................... i What I Need to Know.................................................................................................................................. ii How to Learn from this Module...............................................................................................................ii Icons of this Module.................................................................................................................................. iii What I Know..................................................................................................................................................iv Lesson 1: The Concept of Motion......................................................................................................... 1 What I Need to Know..................................................................................................... 1 What’s New: Scrambled Motion................................................................................. 1 What Is It: The Concept of Motion.......................................................................... 2 What’s More: Acceleration Due to Gravity.......................................................... 4 What I Have Learned:.................................................................................................. 5 What I Can Do: Aristotle and Galileo on Motion................................................... 5 Lesson 2: Uniform Acceleration.............................................................................................................. 6 What’s In............................................................................................................................ 6 What I Need to Know..................................................................................................... 6 What’s New: I Belong...................................................................................................6 What Is It: Uniform Acceleration.............................................................................7 What’s More Free Fall................................................................................................ 9 What I Have Learned: Motion CERA..................................................................... 10 What I Can Do: Caption Time.................................................................................. 10 Lesson 3: Cause of Motion............................................................................................................................ 11 What’s In............................................................................................................................ 11 What I Need to Know..................................................................................................... 11 What’s New: Pick Me Up.............................................................................................11 What Is It: Cause of Motion.......................................................................................12 What’s More: Inertia in Motion..................................................................................13 What I Have Learned: Looking Back.......................................................................14 What I Can Do: Friction Imperfection.......................................................................14 Summary................................................................................................................................................... 15 Assessment: (Post-Test)...................................................................................................................... 16 Key to Answers......................................................................................................................................... 18 References................................................................................................................................................. 19 What This Module is About Dear Learners, Teachers and Facilitators! How are you today? Welcome to this Physical Science Self-learning Module. This material will sharpen your understanding of Mechanics—the study of motion and its causes. It provides explanations of many phenomena such as the motion of freefall, projectile and why we jerk when the vehicle suddenly stops. Repeated experimental observations describes some its aspects in Scientific Laws. These universal laws always apply under the same conditions and imply that there is a causal relationship involving its elements. Discover these laws of Physics and you will sharpen your intuition of nature! This module covers the following lessons: Lesson 1: The Concept of Motion Lesson 2: Uniform Acceleration Lesson 3: The Cause of Motion What I Need to Know At the end of this module, you should be able to: 1. Compare and contrast the Aristotelian and Galilean concepts of vertical motion, horizontal motion, and projectile motion.(S11/12PS-IVc-46); 2. Explain how Galileo inferred that objects in vacuum fall with uniform acceleration, and that force is not necessary to sustain horizontal motion (S11/12PS-IVc-47); 3. Explain the subtle distinction between Newton’s 1st Law of Motion (or Law of Inertia) and Galileo’s assertion that force is not necessary to sustain horizontal motion (S11/12PS-IVd-51) How to Learn from this Module To achieve the objectives cited above, you are to do the following:.1. Carefully read and follow instructions. 2. As a courtesy to the future users of this module, PLEASE DO NOT WRITE ANYTHING ON ANY PART OF THIS MODULE. Write your answer/s on a separate sheet of paper, notebook, workbook or whichever is specified by your facilitator 2. Take the pretest--a simple multiple-choice test provided at the start to determine how much you know about the content of this module. Be very honest in taking the test so you will know how much knowledge you already have about the topic. 5. Read all lessons included in this module. 6. Perform all the activities diligently, as these will help you have a better understanding of the topic. When you need help, tap your parent/guardian, facilitator or contact your subject teacher. 7. At the end of each lesson, take the self-tests to determine how much did you learn with the concept and applications. Cultivate your integrity by doing what is right even if no one is watching. 8. Eventually, take the post test at the end of this module. i Have fun with this self-learning module and may God bless your effort! Icons of this Module Here are the Icons used as your guide in every part of the lesson: What I Need to This part contains learning objectives that Know are set for you to learn as you go along the module. What I know This is an assessment as to your level of knowledge to the subject matter at hand, meant specifically to gauge prior related knowledge What’s In This part connects previous lesson with that of the current one. What’s New An introduction of the new lesson through various activities, before it will be presented to you What is It These are discussions of the activities as a way to deepen your discovery and under- standing of the concept. What’s More These are follow-up activities that are in- tended for you to practice further in order to master the competencies. What I Have Activities designed to process what you Learned have learned from the lesson What I can do These are tasks that are designed to show- case your skills and knowledge gained, and applied into real-life concerns and situations. ii  What I Know Multiple Choice. Select the letter of the best answer from among the given choices. 1. Which of the following statements is true? A. A body can have a constant direction but varying speed and still be accelerating B. A body can have a constant speed but varying direction and still be accelerating C. A body can have varying speed and direction and still be accelerating D. All of these 2. When does an object undergo acceleration? A. when it changes its direction B. when it gains speed C. when it loses speed D. all of these. 3. A ball is thrown upwards and returns to the same location. When it returns, how much is the speed compared with the initial speed? A. half as much B. the same C. twice as much D. four times as much 4. How does Galileo's interpretation of motion differ from Aristotle's? Galileo emphasized A. rates of time B. the acceleration of free fall C. the role of distance in describing motion D. none of these 5. As what you have learned from Galileo, what will happen if you roll a ball along a level surface? A. keep rolling if friction is absent B. roll as long as its inertia nudges it along C. soon roll in the opposite direction D. soon slow down due to its natural place 6. What is the straight line motion caused by the gravitational pull of the earth? A. free fall motion B. horizontal motion C. projectile motion D. none of these 7. How does the acceleration of a stone thrown upward compare to the one thrown downward?. A. greater. B. smaller. C. the same. D. undetermined 8. What will happen to an object if no external forces act on it? A. it will come to an abrupt halt B. it will continue moving at the same speed C. it will move slower and slower until it finally stops D. none of these iii 9. When no forces act on moving objects on air, how can you describe their paths? A. circles. B. ellipses C. parabola D. straight lines 10. Suppose you are riding a motorcycle but it runs out of fuel while driving. The engine stops abruptly but why don't you?  A. because of gravity B. because of inertia C. because of continuation principle D. because of resistance 11. Suppose you are standing in the aisle of a moving bus. If the driver suddenly makes a left turn, why are you likely to lurch to the right? Because of A. an equilibrium challenge B. an unbalanced force C. your momentum D. your tendency to keep moving forward 12. Which of the following best describes an accelerating object? A. object at rest B. object in mechanical equilibrium C. object moving at constant velocity D. object moving slower 13. A ball rolling along a horizontal surface maintains a constant speed. Why is it so? A. friction is present B. no inertia on the object C. no horizontal force acts on it D. surface is smooth 14. Why do a coconut and a bird's feather falling from a tree through the air to the ground below gain speed? A. their velocity changes B. there is a gravitational force acts on them C. their inertia D. their nature to become closer to the Earth 15. Which of the following is true about acceleration due to gravity?. A. it is different for different objects in free-fall B. It is a fundamental property C. It increases in decreasing altitude D. it is a universal constant iv  Lesson The Concept of Motion 1 What I Need to Know A lot of Physics can be observed in daily activities. Motion occurs all around you. It refers to a change in a position of any mass with respect to time. It’s easy to recognize but hard to described. Motion has held the attention of scientists and philosophers since ancient times. In this lesson you will be able to compare and contrast Aristotelian vs. Galilean views of vertical motion, horizontal motion, and projectile motion. What’s New Activity 6.1.1 Find Me Encircle five words which relate to motion. The words can be read horizontally, vertically and diagonally. 1 point each F E C A M N T R S T L O A C P R O J E C T I L E M S S R O A E T H C A V O J Y B R E E S N E E C C E E V E S T H F R D F F L C L F I C A U G S T U T H A E V S C F R I I T U H A U T L E T P I Y O C B I O D E L E L B E E O M R G O N W D E R O G H Y E G R H M E V E R A C H G N J D V R G S Q S F T I N J R T I Z E R R O S T I T E C V S C O G F Y M E N O Y G R F C N W T C G M I S N T T R I B E V 1  What Is It Aristotle thought that heavy objects fall faster than light objects in proportion to their weight. Galileo argued that the motion of a falling body should be nearly dependent of its weight and should have constant acceleration through careful measurements of distances and time experiments. There are several physical quantities that helps described motion of objects. Here are some of them: Distance is the length of the part travelled from starting point to final point. symbol: ∆𝑥 S.I unit: [m] Displacement is the length of the part travelled from the starting point to final point with consideration to the direction. symbol: ⃗⃗⃗⃗ ∆𝑥 S.I unit: [m] Speed is the rate at which distance is covered. 𝑐ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑠𝑝𝑒𝑒𝑑 = 𝑡𝑖𝑚𝑒 𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙 ∆𝑥 symbol: 𝑣 = ∆𝑡 S. I. unit: [m/s] Velocity is the displacement in a given time interval. 𝑐ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = 𝑡𝑖𝑚𝑒 𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙 ∆𝑥 𝑣= ∆𝑡 S.I. unit: [m/s] Acceleration is a measure of how fast the velocity changes with respect to time. Accelerating means moving faster/moving slower and/or changing direction, 𝑐ℎ𝑎𝑛𝑔𝑒 𝑜𝑓 𝑑𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 = 𝑡𝑖𝑚𝑒 𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙 ⃗ ∆𝑣 symbol: 𝑎 = ∆𝑡 S.I. unit: [m/s2] Free fall-a body in vertical motion where gravity is the only force acting on it. It could be an object thrown upward (positive initial velocity), thrown downward (negative initial velocity) or dropped (zero initial velocity). Projectile- a body or a particle in two dimensional motion given an initial velocity and it moves along a curved path under the influence of gravity alone (see figure a) Figure a. Projectile’s trajectory 2  Aristotle and Galileo were two of the most important historical figures that laid the foundation of motion concepts. Their views regarding motion may be oppositey but both helped the progress of science. Table 6A. Views on Motion Motion Aristotelian Concept Galilean Concept Horizontal Force is required to maintain Objects moving in a straight line at motion horizontal motion. a constant speed requires no force to keep them moving. All moving bodies naturally come to rest It will continue in motion due to inertia unless an external force acts on them. Vertical A. Freefall is a natural motion A. Objects move downward motion occurring due to the tendency of because gravity disturbs their nature to established balance to motion. bring disturbed elements to its natural resting place. B. The rate of fall or acceleration of an object is independent of their B. Heavier objects have more mass. earthly elements than lighter ones hence they fall should fall faster. The motion of falling objects is It will take shorter time to reach uniformly accelerated. the ground C. Warmer bodies have an access on fiery elements hence they ascend faster. Projectile The motion of a projectile is parallel A projectile moves two- motion to the ground until it is the object's dimensionalmotion in a parabolic time to fall back into the ground. path The horizontal motion component has zero acceleration (constant speed horizontally) and vertical acceleration is constant. In recent times, the motion of falling bodies has been studied with great precision. When air resistance can be neglected, all bodies experience equal acceleration regardless of their size and weight. This constant acceleration g is called the acceleration due to gravity. The standard value of g at or near the earth’s surface is approximately 9.8 m/s2. 3  What’s More School __________________________________ Date Performed: _____________ Senior High School Date Received: ______________ Physical Science Content (16): _______________ School Year 20__ to 20__ Neatness (3): _______________ First/Second Semester Promptness (3): _____________ Score/Rating: _______________ Name: ________________________________________ Grade/Section: ______________________ Contact Number: __________________________ Teacher’s Name & Signature: ________________ Address: __________________________________________________________________________ Performance Task 6.1 ACCELERATION DUE TO GRAVITY I. Objective: Explain the relationship between speed and acceleration II. Materials: identical coins 2 pcs, table III. Procedure: 1. Label the coins A and B. 2. Place coin A at the edge of a smooth table top so that it hangs over slightly. 3. Place a coin B on the same table top some distance from the overhanging coin A. 4. Slide the coin B across the table (such as by flicking with your finger) so that it strikes the overhanging coin A and both coins fall to the floor below. 5. Repeat Steps 2-4 but this time flick coin B harder so that it will have greater speed as it strikes coin A. IV. Drawing of the Set-up: V. Data and Results: Table 6B. Initial Velocity and g Trial Which coin hit the ground first? 1. Flicking coin B to hit coin A 2. Flicking coin B harder to have greater speed in hitting coin B VII. Observations and Discussions: VIII. Conclusion IX. Guide Question: Does landing of both coins on the floor depend on the speed of the sliding coin? Explain. 4  What I Have Learned Activity No. 6.1.2 Now I Know (Criteria: Critical Thinking-5, Communication 5) Based on the lesson on the concepts of motion, I have realized that _______ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ______________________________________________________. What I Can Do Activity 6.1.3 Show how the Aristotle’s concepts of vertical motion, horizontal motion and projectile motion is similar and different from Galileo through a Venn diagram. 1 point for each correct answer. I. Vertical Motion Aristotelian concept Galilean concept Similarities 5 Lesson Uniform Acceleration 2 What’s In Galileo Galilei having the had the insight and talent to link theory with experiment was regarded as the father of modern science. He did many experiments on the concept of Free fall. What I Need to Know In this lesson, you will be able to explain how Galileo inferred that objects in vacuum fall with uniform acceleration and that force is not necessary to sustain horizontal motion. What’s New Activity 6.2.1 I BELONG Directions: Unscramble the words related to uniform acceleration. Write down your answers in the box. 1 point each 1. ELFELFRA 2. AIGVRYT 3. ARTIGSHT EINL 4. CRJLTOPEEI 5. UAUCVM 6  What Is It Objects in Vacuum Fall with Uniform Acceleration Galileo was interested by the behavior of falling objects. He knew that as falling objects go down, they increase their speed as they go down. This change in speed is acceleration. Although he did not have any tool to measure this change, so he used inclined planes to reduce the acceleration of the moving bodies. He was then able to take a close look at the moving bodies carefully. With his experiments, Galileo proved that regardless of their masses and air resistance two objects dropped simultaneously will reach the ground at the same time. He also discovered that objects fall with uniform acceleration. On his experiment, he had observed the following: After every second, a ball rolling down an inclined plane increases its speed by the same value. Table 6C. Galileo’s Data on a Free Fall Experiment Time (s) Speed (m/s) Acceleration (m/s2) 0 0 1 2 ≈2 2 4 ≈2 3 6 ≈2 4 8 ≈2 6 10 ≈2 The acceleration of the rolling ball increases as the inclined plane becomes steeper. When the inclined plane was positioned vertically, the rolling ball has maximum acceleration. In Table 6B the increase in speed of each object is equal. This experiment approximated Galileo’s observation in free fall. This led him to conclude that regardless of the mass of objects and air resistance, falling objects would always have uniform acceleration when there is no air resistance (e.g. vacuum). What is uniform or constant acceleration? For Galileo, constant acceleration means steady, incremental additions of velocity evenly proportionate to time. The following graphs show the comparison between motion of objects with constant velocity no object with constant acceleration. Figure b. Comparison Between Constant Velocity and Constant Acceleration 7  Positive velocity-indicates the object moves toward the positive direction Negative velocity- indicates the object moves toward the negative direction Positive acceleration-indicates the object is speeding up Positive acceleration-indicates the object is slowing down To have a constant velocity, an object must have a constant speed (steady) in a constant direction. If an object maintains a constant or a uniform change in its velocity in a given time interval along a straight line, then it is said to have a constant acceleration. Force is Not Necessary to Sustain Horizontal Motion Aristotle believed that forces are necessary to keep objects in motion. Although a force is needed to start an object moving, Galileo believed that force was not necessary to sustain motion and did this experiment: Figure c. Galileo’s Experiment on Sustaining Motion Galileo rolled balls down inclined planes and observed and recorded the gain in speed as the rolling continued. On downward-sloping planes, the force of gravity increases a ball’s speed while on an upward slope, the force of gravity decreases a ball’s speed. If smoother planes were used, the ball rolled up the opposite plane closer to the initial height. The difference between initial and final heights was because friction. He postulated the ball would reach exactly the same height if friction could be eliminated. With regards to the ball rolling on a level surface, the ball neither rolls with nor against the vertical force of gravity. It neither slows down or speeds up. It maintains a constant speed. Galileo reasoned that a ball would move forever if it is in horizontal motion. If friction were entirely absent once it is moving, no force is needed to keep it moving except for the force needed to overcome friction. A moving object needs no force to keep it moving. when friction is absent. Such ball would remain in motion all by itself of its own inertia. 8  What’s More School __________________________________ Date Performed: _____________ Senior High School Date Received: ______________ Physical Science Content (16): Content _______________ (15): _____________ School Year 20__ to 20__ Neatness (3): _______________ First/Second Semester Promptness (3): _____________ Score/Rating: _______________ Name: ________________________________________ Grade/Section: ______________________ Contact Number: __________________________ Teacher’s Name & Signature: ________________ Address: __________________________________________________________________________ Performance Task 6.2 FREE FALL I. Objective: Explain uniform acceleration II. Materials: 2 pcs of used bond paper (any paper of the same size), old notebook, coin III. Drawing of the Set-up: IV. Procedure: 1. Crumple up one piece of paper. 2. Hold the piece of paper on one hand and the crumpled paper on other hand at about meter from the ground. Drop them simultaneously. Which falls to the ground faster? Record at table 6D 3. Hold the piece of paper and the notebook at the same height. Drop them simultaneously. Which falls to the ground faster? Paper or notebook? 4. Repeat Step 2 but this time pair the piece of paper with a coin. Complete table A. 5. Repeat Steps 2-4 but this time at a higher height (caution: V. Data and Results: Table 6D. Size and Mass Versus Acceleration Due to Gravity Do the two objects If no, which falls to What happed if the you Pair of Objects reach the ground at the ground first? the same activity more the same time? than 1m above the [Yes/No] ground? Piece of Paper and Crumpled paper Piece of Paper and Notebook Piece of Paper and Coin VII. Observations and Discussions: VIII. Conclusion: IX. Guide Question: What factors the fall of the object? Justify your answer. 9  What I Have Learned Activity No. 6.2.2 Motion CERA-Context, Experience, Reaction, Application (Criteria: Critical Thinking-5, Communication-5) Based on the lesson on uniform acceleration, I have realized that _________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ______________________________________________________. What I Can Do Activity 6.2.3 Caption Time Place your detailed caption below the image to infer Galileo’s explanation on motion concepts: objects in vacuum fall with uniform acceleration and force was not necessary to sustain horizontal motion 1. 2. 10  Lesson Cause of Motion 3 What’s In In the previous lessons, we learned how to described motion. Galileo’s achievements in the study of motion paved way for Newton in his development of the laws of motion. What cause changes in motion? Applied force, you may say but is that really so? What I Need to Know In this lesson, you will be able to explain the subtle distinction between Newton’s 1st Law of Motion (Law of Inertia) and Galileo’s assertion that force is not necessary to sustain horizontal motion. What’s New Activity 6.3.1 Find my Pair Directions: Examine each term numbered 1- 5 and look for the meaning in an online or printed dictionary. Pick the word/s inside the box that best described the term. 1 point each ______________________________________ 1. friction ______________________________________ 2. inertia ______________________________________ 3. net force ______________________________________ 4. external force ______________________________________ 5. constant velocity steady speed in a straight line total force of an object mass originated from outside of the object opposes motion weight constant acceleration at rest vacuum 11  What Is It For nearly 2000 years, the accepted opinion was Aristotle’s concept that moving objects would stop because the natural state of objects was to be at ‘rest’. However, as for Galileo, once the ball is in motion, no force is needed to keep it moving except for the force needed to overcome friction. Friction is an opposing external force that prevents its continued motion. A moving object needs no force to keep it moving when friction is absent. It will remain in motion all by itself. In 1665, Sir Isaac Newton made great revolution in the growth of Science primarily in Physics with his famous Laws of Motion. He established a new set of ideas with His three (3) Laws of Motion that includes the 1st Law of Motion more popularly known as the Law of Inertia. In his original manuscript the Law of Inertia was stated as: “An object at rest is inclined to stay at rest. And an object in motion tends to continue to move in a straight line with a constant speed unless an external force acts on it.” This means that things tend to keep on doing what they are already doing. Notebooks on top of the table are in a rest state, they tend to stay at rest even when you quickly snap the tablecloth or paper underneath. “Everybody tends to preserve in its state of rest, or in state of uniform motion in a straight line, unless it is compelled to change that state by some forces impressed thereon.” If you slide a coin along the road, the coin soon comes to rest. If you let it slide along an ice rink, it slides for a longer time and distance. If you let it slide along a table which it constantly emits air, it continuous to moves. This is because the table offers no friction. A moving object tends to move in a straight line indefinitely in the absence of a force. We can say that Sir Isaac Newton concept was built on Galileo’s. All objects resist changes of motion. This means they all have inertia. Inertia is the natural inclination of any object to maintain state of rest or to remain in uniform motion in a straight line. Resisting changes in its state depends upon its mass. It is the fundamental property of matter for an object to be accelerated or decelerated where it is being opposed. The more mass the object has, the greater is the tendency to resist changes in motion. Newton’s First Law of Motion (Law of Inertia says that if the net force on an object is zero, then the object will have zero acceleration implying that the object is either at rest or moving with uniform velocity. 12  What’s More School __________________________________ Date Performed: _____________ Senior High School Date Received: ______________ Physical Science Content (16): _______________ School Year 20__ to 20__ Neatness (3): _______________ First/Second Semester Promptness (3): _____________ Score/Rating: _______________ Name: ________________________________________ Grade/Section: ______________________ Contact Number: __________________________ Teacher’s Name & Signature: ________________ Address: __________________________________________________________________________ Performance Task 3.3 INERTIA IN MOTION I. Objective: Explain Newton’s First Law of Motion II. Materials: ball, clearly-marked target (i.e., notebook paper, tape or pal), tape measure or ruler III. Procedure: 1. Mark the starting line A and place a target about 10 meters away from it (C). Mark B about 1m (3.28 ft) before the target and mark D 1 m after the target. 2. With the ball on your hand, you are about to sprint towards the target respectively and with a goal to drop the ball on the target. Record your predictions on table 6D. 3. Hold the ball and do not let your elbow leave your side as you sprint toward the target and drop the ball. Do not give the ball an initial velocity; hold the ball from its sides so that you can release freely your grip as you let it drop. 4. Record where the runner released the ball and where the ball strikes the ground. 5. Draw the best diagram for each attempt to drop the ball on the target. Specify where the ball was released and where it actually landed. 6. Repeat the experiment until the ball hits the target. 7. Repeat 2 but this time, do not sprint just run in a slower speed. 8. Repeat 2 but in a walking speed. IV. Drawing of the Set-up: V. Data and Results: Table 6D. Verifying Motion Prediction Motion Prediction Actual Remarks (What will (What happened?) happen?) 1. Running in full sprint 2. Running in reduced speed 3. Walking speed VII. Observations and Discussions: VIII. Conclusion IX. Question: How will you relate today’s activity with Newton's First Law of Motion and with inertia? 13  What I Have Learned Activity 3.3.2 Looking Back Now that you are done knowing motion and force concepts, take a look back and remember the things you learned. (Criteria: Critical Thinking-5, Communication-5) Based on the lesson on inertia, I have realized that ____________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ______________________________________________________. What I Can Do Activity 6.3.4 Friction Imperfection Consider an old book that slides on a table and eventually comes to a halt. Differentiate Galileo and Newton’s concept on why a moving it tends to go to a rest position. 1 point each Table 6E. Galileo Versus Newton on Motion Galileo’s Concept Newton’s Concept Questions 1.What forces are acting on the book? 2. What is the direction of the forces? 3. Compare the magnitude of the force. 4. Are the forces balanced or unbalanced? 5. When does an object comes to its rest position? 14 Summary An object is in motion when it changes position with respect to a reference point. Velocity consists of an object’s speed and direction. Acceleration is a change in an object’s velocity. Objects in vacuum fall with uniform acceleration regardless of mass. Force is not necessary to sustain horizontal motion. 15  Assessment: (Post-Test) Multiple Choice. Answer the question that follows. Choose the best answer from among the given choices. 1. What is the straight line motion caused by the gravitational pull of the earth? A. free fall motion B. horizontal motion C. projectile motion D. none of these 2. How does the acceleration of a stone thrown upward compare to the one thrown downward?. A. greater. B. smaller. C. the same. D. undetermined 3. What will happen to an object if no external forces act on it? A. it will come to an abrupt halt B. it will continue moving at the same speed C. it will move slower gradually until it stops D. none of these 4. When no forces act on moving objects on air, how can you describe their paths? A. circles B. ellipses C. parabola D. straight lines 5. Suppose you are riding a motorcycle but it runs out of fuel while driving. The engine stops abruptly but why don't you? A. because of gravity B. because of inertia C. because of continuation principle D. because of resistance 6. Suppose you are standing in the aisle of a moving bus. If the driver suddenly makes a left turn, why are you likely to lurch to the right? Because of A. an equilibrium challenge B. an unbalanced force C. your momentum D. your tendency to keep moving forward 7. Which of the following best describes an accelerating object? A. object at rest B. object in mechanical equilibrium C. object moving at constant velocity D. object moving slower 8. A ball rolling along a horizontal surface maintains a constant speed. Why is it so? A. friction is present B. no inertia on the object C. no horizontal force acts on it D. surface is smooth 9. Why do a coconut and a bird's feather falling from a tree through the air to the ground below gain speed? A. their velocity changes B. there is a gravitational force acts on them C. their inertia D. their nature to become closer to the Earth 16 10. Which of the following is true about acceleration due to gravity? A. it is different for different objects in free-fall B. It is a fundamental property C. It increases in decreasing altitude D. it is a universal constant 11. Which of the following statements is true? A A body can have a constant direction but varying speed and still be accelerating B. A body can have a constant speed but varying direction and still be accelerating C. A body can have varying speed and direction and still be accelerating D. All of these 12. When does an object undergo acceleration? A. when it changes its direction B. when it gains speed C. when it loses speed D. all of these. 13. A ball is thrown upwards and returns to the same location. When it returns, how much is the speed compared with the initial speed? A. half as much B. the same C. twice as much D. four times as much 14. How does Galileo's interpretation of motion differ from Aristotle's? Galileo emphasized A. rates of time B. the acceleration of free fall C. the role of distance in describing motion D. none of these 15. As what you have learned from Galileo, what will happen if you roll a ball along a level surface? A. keep rolling if friction is absent B. roll as long as its inertia nudges it along C. soon roll in the opposite direction D. soon slow down due to its natural place 16. What is the force required to maintain an object at a constant speed in free space equal to?. A. zero B. the mass of the object C. the weight of the object D. the force required to stop it 17