1 Science Grade 6 Quarter 3 – Module 1: Gravity and Friction 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 royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module 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. Printed in the Philippines by DepEd Cebu City Division, RO VII Office Address: Imus Avenue, Cebu City Telefax: (032) 255-1516 / (032) 253-9095 2 What I Need to Know In this module, you will learn about how gravity and friction work. You will know how they can affect the movements of different objects around us. (S6FE-IIIa-c-1) Here’s a simple guide for you in going about this module: 1. Read and follow the instructions very carefully. 2. Take the pretest provided at the start to determine how much you know about the content of this module. 3. Be very honest in taking the test so you know how much knowledge you already have about the topic. 4. Read carefully the lesson included in this module. 5. Perform all the activities, as these will help you have a better understanding of the topic. 6. Finally, take the post-test at the end of the module. After studying this module, you should be able to: ● define gravity and friction ; ● describe how gravity and friction work ; ● infer how gravity and friction affect movements of different objects. 3 What I Know (Pre-test) A. Read each question carefully and write the letter of the correct answer on your answer sheet. 1. Which of the following statement is NOT true? Gravity ________ . A. draws object toward the center of the Earth C. pushes an object upward B. determines your weight here on Earth D. pulls object downward 2. A boy sits on a grassy slope. Which of these stops him from sliding down? A. friction B. gravity C. magnetic force D. weight 3. Where is the gravitational force directed as you stand on the floor? A. backward B. downward C. forward D. upward 4. What force do the brakes on a bicycle produce to stop the bike? A. friction B. gravity C. magnetism D. all of the above 5. Which shows that sometimes friction is undesirable? A. pushing furniture C. walking on wet floors B. lighting a matchstick D. using the brakes when approaching a stoplight B. Identify if the forces acting on the situations given below is gravity or friction. Write the answer on your answer sheet. __________ 6. A car parked on a sloping road. __________ 7. A skydiver falls through the air with her parachute open. __________ 8. The moon revolves around the Earth. __________ 9. You write a letter on a piece of paper using your pen. __________ 10. You keep on walking on Earth instead of floating away into space. Well, how was it? Let’s see if you get it right. Compare your answers with those in the Key to Answers on page 11. 4 What’s New What is it How do gravity and friction work? GRAVITY AND MASS Anything that goes up ultimately goes down. Things do not fly off the Earth’s surface. This is because Earth is exerting a strong attractive force on you and the things around you. This force is called gravity. Sir Isaac Newton discovered the principle of gravity. According to this principle, everything in the universe, big or small, exerts gravity on other things. Since Earth is massive, it strongly attracts anything on its surface. The same concept keeps the planets, and other 5 heavenly bodies in place. Since the Sun is more massive than all the planets, its gravity pulls them around its orbit. GRAVITY AND WEIGHT The gravitational force exerted by the Earth on an object is equivalent to the object’s weight. The greater mass an object has, the greater its weight. Heavier objects like the appliances in your house weigh more, than lighter objects such as books and pens. If the Earth’s mass is increased, the weight of objects in it will also increase. On the other hand, if you go to the moon your weight becomes much less because the moon is smaller, has less mass and has weaker gravitational pull than Earth. GRAVITY AND DISTANCE Gravity is a noncontact force. It acts between objects even if they are separated and far from each other. The farther two objects are from each other, the smaller gravitational pull will be between them. Astronauts in space stations and space crafts can float around and do the space walk. They are not weightless. They still have weight, but since they are far from Earth, it is less, than when they are on the ground. FRICTION Friction is a force between two bodies which are in contact with each other. It stops an object from sliding against a surface or another object by acting in the opposite direction of the sliding movement. Take for example, a moving car. When the driver wants to stop the car, he or she steps on the brakes. The brakes apply force on tires, causing friction to slow down and stop the tires. 6 What’s More A. Marble Race Problem: How do gravity and friction affect movements of objects? What you need: two identical rulers with a groove in the center two small marbles ; one large marble books ; baby powder / flour What you need to do: Set up 1 1. Place the two rulers side by side. Then, elevate them by the use of a large book. 2. Set the big marble in the groove of the first ruler and the small marble in the groove of the second. Starting points should be the same. Which do you think will reach the bottom first? 3. Then, release the marbles. Use the table like the one below to record your observation. Make three trials. 4. Put another book on your set up to raise the elevation. Repeat step 3 and then, record your observation. 5. Again, place another book in your set up making the ramp more steeper. Repeat step 3. Make three trials. Set up 2 6. Now, sprinkle baby powder/flour on the first ruler. Place one small marble on it, and the other small marble on the ruler without powder. Release the marbles and observe. Make three trials. Trials Elevation 1 2 3 with one book with two books with three books What have you found out: 1. What force causes the marbles to fall? ___________________________________ 2. In set up 1, which of the marbles reach the bottom first? The small or the big marble? Explain your observation. ___________________________________________________________________ 7 ___________________________________________________________________ 3. In set up 2, which marble reach the bottom first? ruler with baby powder/flour or ruler without baby powder/flour? Why is this so? __________________________________________________________________ 4. How does the baby powder/flour affect the amount of frictional force between the marble and ruler? ________________________________________________________________ Conclusion: How do gravity and friction affect movements of objects around us? ______________________________________________________________________________ B. Copy the table below on your answer sheet, then list the things that might happen if there is no gravity and friction. What might happen if there is no gravity? example: Oceans will drift into space. What might happen if there is no friction? example: Walking on the road would be difficult. 1. 1. 2. 2. Let’s do More A. Complete each statement using the words in the box. Write the answer on your answer sheet. 1. All objects fall toward the ___________ of Earth. 2. The farther you are from Earth, the ____________ your weight. 8 3. All objects are attracted to each other because of __________. 4. The gravity between two objects decreases as the distance between them______. 5. The more distant the body from Earth, the _________ gravitational force of attraction is. B. Modified True or False. Write True if the statement is correct and change the underlined word/s if it is wrong to make it correct. Write the answer on your answer sheet. _____ 6. Gravity is a contact force that acts between two separate objects. _____ 7. Gravity on the moon is less than the gravity on Earth. _____ 8. Friction keeps objects from sliding off surfaces. _____ 9. Friction is the force that opposes the push of gravity. _____ 10. Gravitational pull between objects increases as the distance between them decreases. What I Have Learned Read each question carefully and write the answer on your answer sheet. 1. What is gravity? ___________________________________________________________ 2. Differentiate gravity from friction? ___________________________________________________________ ___________________________________________________________ 3. Why do objects fall toward the center of the Earth? ___________________________________________________________ ___________________________________________________________ 4. How does friction affect the motion of an object? __________________________________________________________ __________________________________________________________ 9 What I Can Do Read carefully the situation below and do the task on your answer sheet. Friction occurs between the parts of the vehicle and between the road and the tires. Wearing away of parts in engines sometimes causes road accidents. Create a display advertisement or slogan to show road safety, persuading road users to adopt safer attitude that decreases transport-related injuries and deaths. Assessment! (Post-Test) A. Read each question carefully and write the letter of the correct answer on your answer sheet. 1. Which of the following best describes friction? It is a force that occurs _____ . A. between solids B. only on rough surfaces C. between solids and liquids D. when surfaces touch each other 2. Where is the gravitational force directed when you are holding a glass? A. away from the glass B. downward C. into the glass D. upward 3. Which of the following shows the presence of friction? A. cars continuously roll down hills C. people stay in place as they move B. things fall off on smooth surfaces D. cars stop when the driver steps on the brakes 4. How distance between two objects affects the pull of gravity? The ___________ A. lesser the distance, the lesser the gravitational pull between them B. greater the distance, the lesser the gravitational pull between them C. greater the distance, the greater the gravitational pull between them D. gravitational pull between them depends on their weights 5. Why does a car travel faster in going down than in going up? It is ______________. A. pushed by the wind C. moving toward gravity B. moving against the gravity D. pulled by the weight of the car B. Identify if the forces acting on the object described in each situation below is gravity or friction. Write the answer on your answer sheet. 10 __________ 1. A deliveryman uses a ramp to slide off packages easily. __________ 2. A meteor falls down through the Earth’s atmosphere. __________ 3. A boy rides a bicycle on the road. __________ 4. A ball thrown in the air comes down. __________ 5. The vehicles slow down the road during the rainy season. Key to Answers: Let’ Do More A. 1. friction 2. gravity 3. friction 4. gravity What I have Learned 1. Gravity is a noncontact force that acts between objects even if they are separated and far from each other. 2. Friction is a force between two bodies which are in contact with each other. 3. because of gravitational pull 4. - it slows down motion of objects - it stops motion of objects -it prevents objects from sliding 5. friction B. 1. center 2. lesser 3. gravity 4. increase 5. less References: A. Books: Sarte, Evelyn T., Science Beyond Borders 6, DepEd-BLR, 2016 Padpad, Evelyn C., The New Science Links 6 : Rex Bookstore Inc., 2015 San Pablo, Jovita H., Real-Life Science 6 : Abiva Publishing House, Inc., 2016 11 B. Images: https://tinyurl.com/tstgls8l https://www.pinclipart.com/pindetail/ibixRxb_drawing-of-kid-on-roller-coaster-clipart/ https://www.pinclipart.com/pins/friction/ https://tinyurl.com/1easyidg https://tinyurl.com/jbtla4nr https://tinyurl.com/1easyidg https://tinyurl.com/y4qdk4hk - End of Module - 12
