SCIENCE VI

GRADE VI OXYGEN-CARBON DIOXIDE CYCLEAt the end of the module, you should be able to:  Describe the interrelationships among living organism in an ecosystem for gas (oxygen-carbon dioxide cycle) Try to RecallA. Write the answers in your notebook.1. Complete the diagram below with words, to show what plants needs in manufacturing their food during the process of photosynthesis in order to grow. AB CD2. Complete this: H2O + Minerals + Sunlight + CO2 → ______ and ______ B.

1. Study the diagram below. Fill in the blank below with the gas that you exhale and inhale. _______? _______? 2. Answer the questions below. a. What gas do humans exhale? b. What gas do humans inhale? c. What happens to the gas that we exhale? d. Where does the gas that we inhale come from? e. What gas do we take from plants? f. What can you call the cycle shown in the diagram? Why? g. What would happen if there were no plants or animals? h. Is it important to maintain a supply of these gases? Why?.

ExploreActivity 11. Copy the phrases below in your notebook and match each of the following sentences with the number indicated in the diagram it best describes. (Write the number in the box.)  the by-product of photosynthesis  the gas needed by plants in making food  the process by which plants manufacture food  the organisms that need oxygen in order to survive  the process of taking in oxygen and giving off carbon dioxide  releases oxygen during photosynthesis

Read and learn more.  Plants and animals depend on each other in many ways.  The continuous exchange of oxygen and carbon dioxide by plants and animals including man is called oxygen-carbon dioxide cycle.  Plants need carbon dioxide in the process of photosynthesis.  Carbon dioxide is a waste product produced when man and animals respire.  One of the by-products during photosynthesis is oxygen which is needed by animals and humans in order to live.  The oxygen-carbon dioxide cycle is very important to keep both plants and animals alive. Apply It1. Construct your own oxygen-carbon dioxide cycle using the following organisms: rice plant – bird2. If you are given a chance to choose, what kind of place would you like to live in? Why? a) A place with many trees b) A place with wide space but lesser trees

Test Yourself* Write a 4-5 sentence paragraph about oxygen-carbon dioxide cycle using the illustration above.

GRADE VI PHYSICAL CHANGEAt the end of the module, you should be able to:  Show that materials may change in size, shape, volume or phase  Observe that no new material is formed when physical change took place Try to RecallActivity 1Study the following pictures. Tell whether each object is SOLID, LIQUID or GAS writeyour answer in your notebook. 1. 4. 2. 5. 3.Activity 2

Write the unit of measurement use to measure these materials. Do it in your notebook.1. 2. 3.Activity 3 What changes happened to materials? Write the answer in your notebook. 1. 2. 3. 4. 5.

ExploreDo you see the changes that happen to materials?How do these materials change?Is it possible to change a material and return to its original form?Find out the answers by doing these activities.Activity 1What you need: A piece of paper popsicle sticks fruit (any) yarn, any string, nito or rattan strips knife ½ yard of soft wireWhat to do:1. Construct a paper boat or airplane using a piece of paper.2. Slice the fruit in half.3. Make a vase or any object out of sticks. Tie the edges together with yarn, string, nito or rattan strips.4. Form the soft wire into a interesting object or shape.Answer these:A. What changes take place in the paper sticks fruit wireB. Are there new materials formed? Did the materials remain the same?C. Can the materials be returned to their original form?If materials returned to their original form, physical change took place.

Activity 2What you need: 2 drinking glasses ice cubes kettle or small pot with water marker or crayon bar or detergent soap bowl or basin of waterWhat to do:1. Put some ice cubes in a glass. Observe.2. In another glass, with water. Pour water in a kettle or pot. Measure the amount of water with a marker. Boil it for 10 minutes. (Ask the help of an adult). Cool then before pour back to the glass. Then, measure with a marker.3. Dissolve the powdered soap in a basin of water.Answer these: A. What are the materials used? B. What became of the ice cubes? water? soap? Are there new materials formed? C. How these materials changed? D. Can these materials return to their original form? How? E. What do you call this kind of change?

Read and learn more.In physical change, only the physical properties or characteristics of thesubstance changed and it is still the same substance and no new material isformed. It takes place when a substance is heated and expands, or is cooled andcontracts. The substance can be changed back into its original size shape,volume or phase. There are different ways of showing physical change likefolding, cutting, mixing, freezing, melting, bending, pasting, sewing, sawing orstretching. I LEARNED THAT:  Materials may change in size, shape, volume or phase  No new material is formed when physical change takes place  Physical change is shown by folding, slicing, tying, stretching, melting, heating, etc.

Apply ItAnswer the following:A. Instead of throwing scratch paper, what can you do to make them useful?B. Plastic and canned containers must be recycled / reused. What materials/projects can you think of to make them usable?C. Write PHYSICAL if the situation shows physical change and NOT PHYSICAL CHANGE if the situation does not show a physical change. 1. broken glass 2. cross-stitching 3. making a paper mache of animals 4. designing a paper bag puppet 5. burning paper

Test Yourself*A. Put a check mark (√) if the illustration shows a physical change and a cross mark (x) if not. Do it in your notebook. 1. 4. 2. 5. 3. 6.

B. Prepare a table like one below in your notebook. On the left columns are materials. Fill in the next column with the way the materials undergo physical change. Do it in your notebook. Material How it undergoes physical change1. paper cutting, folding, rolling, tearing2. candy wrapper3. piece of wood4. beads5. string or rope6. bread

Key to Correction How it undergoes physical change cutting, folding, rolling, tearingTry to Recall cutting, folding, tearing sawing, carvingActivity 1. What Matters Most! stringing, grinding1. SOLID cutting, tying2. GAS cutting, slicing3. LIQUID4. SOLID5. GASActivity 2: Take Note of the Size1. LITER2. MILLIMETER3. GALLONActivity 31. YES2. YES3. NO4. YES5. YESTEST YOURSELF1. √2. √3. √4. √5. X6. √B. Material 1. paper 2. candy wrapper 3. piece of wood 4. beads 5. string or rope 6. bread



PRESERVING THE ENVIRONMENT GRADE VI PRESERVING THE ENVIRONMENTAt the end of the module, you should be able to:  Demonstrate commitment and concern in preserving/conserving the balance of life in the ecosystemTry to RecallA. Match column A with the description on column B. Write the letter of the correct answer in your notebook.1. Muro Ami a. big and small fishes are killed when chemicals are used2. Dynamite fishing b. clearing and burning of ground cover to be planted with crops3. Illegal logging c. young trees are cut without replacing them4. Improper waste disposal d. coral reefs are destroyed just to catch fish5. Kaingin system e. homes of plants and animals are destroyed and may cause flash floods6. Deforestation f. dumping of garbages in land and bodies of waterB. List down three natural calamities that hit our country.

ExploreIn this lesson you will learn how you can preserve and conserve the environment.Activity 1  The items listed in the chart are telling some problems that caused imbalance of life in the ecosystem.  Can you suggest ways to solve these problems? Problem Ways of controlling/preventing1. burning garbage2. using pesticides and herbicide3. cutting of trees4. kaingin5. Muro-Ami Fishing

Activity 2  The following can help protect our environment. How does each help protect our environment? 1. Recycling garbage 2. Clean and green project 3. Save the Earth movement 4. Providing Sanctuaries 5. Reusing water 6. Sagip Ilog 7. River clean Up Drive  Look at your community. What is the environmental problem happening at this time? Make a simple plan on how you can solve this environmental problem in your community.  Follow the PROJECT PLAN below. PROJECT PLAN I. Title: II. Objective: (the reasons why you want to do this project) III. Where is the project location: IV. When will you do it: V. Who can help you: VI. What will you do:

Read and learn more. To prevent global warming (the rise in global temperature), we should reduce the burning of fossil fuels and ensure that we have lots of trees. A growing tree can process about 20 kilograms of carbon dioxide a year. The restoration and maintenance of the balance of life in an ecosystem will help ensure the survival of future generation. The DEPARTMENT OF ENVIRONMENT and NATURAL RESOURCES (DENR) is responsible in addressing the environmental issues and problems. They enforce the following programs:1. Sanctuaries - places where hunting and fishing are not allowed (prohibited) - areas where endangered plants, animals and marine life are taken care of.2. Clean and Green - encourages people to plant trees and practice proper waste disposal.3. Sagip Pasig - a campaign to help clean the Pasig River.4. Save the Earth Movement - aim to take good care of the forest and endangered species.5. Recycling Garbage Project - encourages people to re use Like paper, bottles cans, wrapper, plastics and other recyclable materials.I LEARNED THAT:  Conservation is the wise use of resources available.  You should involve yourself in the preservation and conservation of our environment. To sustain economy balance and ensure the survival of future generations.

Apply It1. Interview your barangay captain on the programs initiated in preserving and or managing the following: 1. forest 2. rivers 3. garbage disposal2. If you could join an environmental group campaign which program would you like to join? Why?* Test Yourself What will you in the following situations? 1. You observes that your classroom is clean. You can’t find any trash can, what will you do to maintain the cleanliness? 2. You often see your friend throwing their garbage into the river. What can you do to stop that practice? 3. Your friends are catching birds, butterflies, and other small animals. What will you tell them?

GRADE VI SOUND ENERGYAt the end of the module, you should be able to:  Identify energy uses and sound Try to RecallStudy the type of energy shown in each picture.Identify whether it is electrical energy, light energy, chemical energy. There may be oneor more answers.__________________ ____________________________________ __________________

Explore Close your eyes and listen. Name the sounds you hear. How many did you hear?In this lesson you will learn more about sounds.Activity 1What you need: rubber band fork and spoonWhat to do: 1. Get a rubber band. Stretch the rubber band tight with your fingers. Let your partner pluck the rubber band.  Was sound produced? 2. What movement was produced by the rubber band? 3. Use shorter rubber band. Was the sound produced louder? softer? If you use longer rubber bands, what kind of sound is produced? Did you know that… sound is a form of energy that causes molecules of a medium to vibrate back and forth. vibration is the back and forth, up and down motion of an object.

Activity 2What you need:cloth or balloon small pieces of papergrains of sand can or bowlrubber band stickWhat to do:1. Wrap the mouth of the can or bowl with a cloth or balloon.2. Secure it with a rubber band.3. Sprinkle small pieces of paper or grains of sand on top of the cloth or balloon.4. With a stick, slowly tap the cloth. Then tap it with a stronger force.5. Observe.Answer these:1. What happened to the pieces of paper/grains of sand?2. What caused the pieces of paper/grains of sand to move?3. When did the pieces of paper/grains of sand move faster?4. When the pieces of paper/grains of sand moved fast, what was the kind of sound produced?5. How can you relate force, vibration and sound produced in this activity?

Activity 3What you need: 8 identical pep bottles drinking straw (Waxed paper straws work better than plastic)What to do: 1. Fill eight identical bottles with different amounts of water as shown. Number the bottles 1 to 8.  Which bottle has the longest length of air (more air inside). 2. Blow across the lips of the bottles.  Do all bottles give off the same sound?  Which bottle produced the highest note? The lowest note? 3. Arrange the bottles to make a musical scale from the lowest to the highest note.  What can you say about the length of air space and the sound produced?  Show the relationships. longest space of air = ______ sound is produced shortest space of air = ______ sound is produced

Activity 4 a big pail or can of water 2 rocks What you need: a meterstick a pencilWhat to do: 1. Get a meterstick and a pencil. 2. Hold the meterstick close to your ear. Have a partner scratch the other end of the meterstick with a pencil.  What happens? 3. Hold the meterstick away from your ear and repeat the activity.  Did you hear a lesser sound?  Where does sound travel faster? 4. Get a big pail of water. Get 2 pieces of rocks and hit them together under water. Now, hit them together out of water.  Did you hear sounds when you hit the objects together? Why?  Which sound was louder, in air or water?Did you know that… Solid is a better transmitter of sound than liquid. Liquid is a better transmitter of sound than gas.

Activity 5 List down different sources of sound. Identify some uses of these sound. An example has been done for you. 1. radio – listen to musicI LEARNED THAT:  Sound is a form of energy that causes molecules of a medium to vibrate back and forth. It is used for communication and entertainment.  Sound is produced by things that are moving or vibrating. When an object moves, it makes the air surrounding it vibrate. The vibrations are called sound waves. We hear sound when sound waves that are travelling through the air or another material reach our ears.  Sound is transmitted through a medium.  speed of sound in steel – 5,200 m/sec  speed of sound in water – 1,500 m/sec  speed of sound in air – 340 m/sec  Some sounds are loud, soft, pleasant or unpleasant.  Music is made up of sounds that are produced when people sing or when musical instruments are played. Music is used for entertainment and communication.

Apply It What should a motorist do when he hears the sirens of an ambulance or a fire truck engine behind him?* Test YourselfIdentify 5 sounds and describe the use of 3 of these sounds. An example is given below.

Key to CorrectionTry to RecallExploration Time Activity 1 Activity 2 Activity 3Apply it 1. 2.Test Yourself 1. solid 2. gas 3. water 4. fastest 5. slowest

GRADE VI SPACE MISSIONSAt the end of the module, you should be able to:  Name some space probes and their missions  Name some achievements/problems met in space exploration Try to Recall Study the picture.Answer these: A person high up in the air with1. What’s in the picture? a parachute2. Infer on how long can a man on a parachute stay up in the air?3. What do you think is the purpose of the man in doing such action?4. To what object is this parachute comparable to?5. Why do you say so?

Explore Everyone of us want to know the missions and achievements of the different spaceprobe. Am I right?Here are some.Activity 1 Probe Date Launched AchievementsLuna 2 September 12, 1959 First probe to hit the moonLuna 3 October 4, 1959 Took first pictures of the moon’s far sidePioneer 5 March 1960 Gathered information about deep spaceMariner 2 August 1962 First probe to VenusRanger 7 July 1964 Took photographs of the moonMariner 4 November 28, 1964 First probe to MarsLuna 9 January 31, 1966 First probe to soft-land on the moonVenus 7 August 17, 1970 First probe to land on VenusLuna 16 September 12, 1970 Brought back moon samples automaticallyMariner 9 May 30, 1971 Took photographs of Mars First probe to Jupiter, studied itsPioneer 10 March 10, 1972 atmosphere, radiation belt, magnetic field and satelliteMariner 10 November 3,1973 Explored Venus and Mercury. Mercury is April 5, 1973 full of craters.Pioneer 11 First probe to Saturn July 1976 Set up a weather station on Mars scoopedViking up Martian soil and conducted experimentsLander to look for signs of life it. Obtain vital information and getVoyager 1, 2 1977 photographs of Jupiter, Saturn, Uranus, and Neptune. Voyager 2 reached Neptune in August 1989.Answer these:1. Based on the table where did the probes explore?2. What are some of their achievements?3. Why do you think space probes choose/select different kinds of planets to be their mission?

A. Man has gone beyond the earth.Here are some of their space travels.SPACE TRAVELSSputnik I This is the first satellite artificially launched by Russians on October 4, 1957.Sputnik II The second satellite launched by Russians on November 3, 1957 which providedsome information on the effects of the sun’s radiation and cosmic rays. Along with it wasa trained dog named Laika.Explorer I The first artificial satellite launched by Americans on January 31, 1958. It was ableto identify the Van Allen Belt - a zone surrounding the earth with intense radiation.Vostok I The first manned space flight, sent off by Russians on April 12, 1961. It was YuriGagarin, a Russian cosmonaut, who became the first man in space. He orbited the earthfor 1 hour and 48 minutes.Vostok 6 This was launched on June 16, 1963. Valentina Tereshkova, the first woman inspace, manned this spacecraft.Vokshod 2 This was sent off on March 18, 1965 and manned by two Russian cosmonauts, PavelI. Belyayev and Aleksei A. Leonov. The latter spent 10 minutes outside the spacecraft,and that made him the first man to walk on space.Gemini 4 Gemini 4 was manned by Edward White. He stayed outside the spacecraft for 21minutes on June 1965. He was the first American astronaut to walk in space.Apollo 11 The first moon landing was made successfully by Apollo II on July 20, 1969.Astronauts Neil Armstrong and Edwin E. Aldrin descended in the eastern side of themoon. The fist step was made in the moon by Neil Armstrong. Michael Collinsremained in the command module, and was responsible for communication with the baseon earth.Space Prober They are robots sent to study the planets in our solar system.Pioneer This probe was sent to Saturn and revealed that winds can blow at speed of about1,500 kph.Voyager 2 It left the earth in 1977 and passed by Jupiter, Saturn and Uranus. It was able to reachNeptune in 1989.Answer these:

Name the achievement of the following astronaut, cosmonaut, satellite or spaceprobe.  Neil Armstrong ____________________________________________  Yuri Gagarin ______________________________________________  Valentina Tereshkova ______________________________________  Sputnik I and II ____________________________________________  Voyager II ______________________________________________Activity 2 The astronauts in the pictures are inside the spaceship. Name the problems that theywould encounter in space. What are some of the problems met by astronauts in space?___________________ ______________________________________ ______________________________________ ______________________________________ ___________________ How did the astronauts solve these problems?

Read and learn more. First men to explore in outer spaceNeil Armstrong Yuri Gagarin(First astronaut to land on (Russia’s first man inthe moon) space)Allan Shepard Valentina Tereshkova(America’s first astronaut) (First woman in space)

SPACE TRAVELS PROBE DATE LAUNCHED ACHIEVEMENTSVenera13,14 October, Landed on Venus, drilled surfaceVega 1, 2 November 1981 rocks and analysed them in a smallGlotto laboratory.Magellan Both probes flew by Venus, droppingGalileo December 1984 landers and balloons, flew on toUlysses intercept Hally’s comet.ClementineMear July 2, 1985 Close interception of Halley’s comet.Mars Global Provided the first detailed radar mapsSurveyor May 4, 1989 of the Venusian surface, concludingCassini with the first aerobraking manoeuvresMars Polar in the planet’s atmosphere.Lander Orbiter entered the Jovian System October 17, 1989 December 1995, sending a probe deep into the atmosphere of Jupiter. Swung out to Jupiter’s orbit before October 6, 1990 describing an arc over the poles of the Sun. January 25,1994 Small spacecraft in lunar polar orbit for mapping and geological study. First dedicated mission to the February 17, 1996 asteroids, scheduled to intercept asteroids Mathilde and Eros. Mission to map Mars Pathfinder November 7, 1996 lander touched down on July 4, 1997; Sojourner robot vehicle rolled off and began exploration July 5. Probe scheduled to enter orbit around October 15, 1997 Saturn in 2004, while Huygens lander detaches and lands on Saturn’s moon Titan. Probe scheduled to land near southern January 3, 1999 polar cap of Mars and conduct soil analysis, searching for possible signs of life in Mars’s past.

 The landing on the moon by Neil Armstrong and Edwin Aldrin was one of man’s greatest achievements in space explorations. Some of the problems encountered by man during space explorations are:  Airlessness  Weightlessness  Extreme heat and radiation  Food intake  Waste disposal As we know without air, man cannot live, specially in outer space which is a vacuum, an airless and weightless environment. To make space travel possible, the spacecraft is provided with oxygen at a pressure tank, and a spacesuit with a breathing mechanism is needed. Space explorations important achievements are:  More insights of the different planets  Easy communications satellite  Space stations  Probes on stars and other heavenly bodies  Better understanding of the Universe Astronauts – term used referring to American scientist who had traveled in space. Cosmonaut – term used referring to Russian scientist who had traveled in space. Spacesuits - are designed for the harsh conditions in space. It has several layers that can help an astronaut or cosmonaut adjust to extreme temperature change. Provides outside air pressure and protect the astronaut or cosmonaut from cosmic and ultraviolet rays.

Solutions to the problems of astronauts or cosmonauts on space Preparing for the space travel, meeting the hazards during the travel and returning to Earth from space have many problems. For many years, scientist have developed materials and procedures that will overcome these problems for successful space travel. Before the Space Flight  In building the spaceship, special metals and insulation materials were used to protect the spaceship from being burned in the atmosphere due to friction.  The astronauts were given physical care and training to make them ready for the flight. During Space Journey  Sufficient supply of oxygen, food and liquid which can last throughout the travel should be prepared.  The astronauts should learn how to cope with the weightlessness and lack of activity while in space.  They should be safely held in place during rapid acceleration while leaving the earth and during deceleration when returning into the atmosphere. After the Space Travel  As a spacecraft returns from its journey into outer space, it must plunge into the atmosphere before it can land. This is called reentry.  The astronauts and the spaceship were properly prepared for their safe reentry.  The astronauts were given activities and physical examination that will help them to adjust to their natural environment again.

Apply ItA. Suppose your are going into outer space with your friends, what are the things that you will prepare? What are the necessary precaution that you must do? An Astronaut

Test Yourself*Match column A with the description with column B. Write the letter of the correctanswer. A B1. Luna 3 A. The first American astronaut in outer space.2. Pioneer 10 B. Manned space flights that brought3. Neil Armstrong astronaut to the moon.4. Sputnik I C. The first manned spacecraft that orbited the earth.5. Vostok I6. Apollo II D. Took first pictures of the moon’s far side7. Allan Shepard8. Valentina Tereshkova E. First probe to Jupiter9. Mariner 4 F. First man to step foot on the10. Mariner 9 moon11. Yuri Gagarin G. First woman in space H. The first artificial satellite which began the “space age.” I. First man to orbit the earth J. First probe to Mars

Name the problems of astronaut in space as stated below. Select your answer in the box. ____________ 1. Food cannot be taken with the use of hands. ____________ 2. Ultraviolet rays coming from the sun would strike the spacecraft. ____________ 3. Outer space is 0 gravity. Objects/persons in space would float. ____________ 4. Astronauts don’t have trash can to put their garbage. ____________ 5. In space there is no air. It is like a vacuum. weightlessness radiation proper waste disposal food intake airlessness

Key to CorrectionTry t o RecallExploration Time Activity 1 Answer these Activity 2 Answer these Activity 3 Answer theseApply itTest YourselfA. 1. G 6. C 2. F 7. H 3. E 8. D 4. A 9. K 5. B 10. IB. 1. food intake 2. radiation 3. weightlessness 4. proper waste disposal 5. airlessness

GRADE VI SPEED, VELOCITY, ACCELERATION AND FRICTIONAt the end of the module, you should be able to:  Identify factors affecting movement  Show that external conditions affect the movement of bodies (friction) Try to Recall In a “Tug of War” game between Team A and B, Team A was the winner. Whatmade team A win? Put a check (√) on the blank before each number that explains theanswer. ___ 1. Team A had greater force than Team B. ___ 2. There was an unbalanced force. ___ 3. Team B moved to the direction of Team A. ___ 4. Team A had lesser force.

ExploreHave you ever ridden a car or a tricycle with closed eyes?  Closed eyes, can you feel if your car is moving slow or fast?  Closed eyes, can you feel if the car is changing direction?Find out the exact movement of moving objects in these activities.Activity 1What you need:two rulera booka marblestopwatch or watch with second handWhat to do:1. Get 2 rulers. Tape together the end of the two ruler. Set one end of the ruler on the edge of a book as shown. Roll the marble on the groove of the ruler. Do this 5 times.2. Using a stopwatch, take note of the time it takes for the marble to travel the length of the 60 cm ruler.3. Record it in a table similar to the one below. Trial Distance Time in Speed seconds 1 60 cm 2 60 cm 3 60 cm 4 60 cm 5 60 cm4. Compute the speed of the marble in cm per second by using this formula. If the marble travels 60 cm in 5 seconds.

speed = distance traveled time speed = 60 cm 5 seconds speed = 12 m/sDistance (km) 5. Study the graph of the speed of a runner . 30 4 20 10 0 1 23 Time (hr)  What is the speed of the runner after the 1st hour?  What is the speed of the runner on the 2nd hour?  Is the speed the same? Is there an additional distance covered? Speed that remain the same is called constant speed.  At the end of the 4th hour, what is the speed?  Compute the average speed of the runner?  What data are needed to find the average speed of a running object?  Based on the activity how would you define speed?

Activity 2Study the table below.Give the velocity of each bus. The first one is done for you.Car Speed Direction VelocityA 50km/hr North 50km/hr, NorthB 50km/hr South _____________C 50km/hr West _____________D 50km/hr Northeast _____________E 50km/hr West _____________  Which cars have the same speed? Why?  Which cars are traveling in the same direction?  Which cars have the same velocity? Why?  What factors are considered in finding velocity?  Based on the activity how would you define velocity?Did you know that… velocity is the speed of a moving object in a specified direction. velocity changes when there is change in any of the following: change in speed change in direction change in both speed and direction when an object moves with the same speed and direction, it has constant velocity.

Activity 3What to do: 1. Trace with your finger the path taken by the bus. a. Bus X is traveling with a speed of 20km/hr, North. b. In the first corner, it turned left with the same speed. c. Then it turned right, moving at 25 km/hr, North.  What changes took place as the bus traveled?  Was there change in speed? Change in direction?  Was there change in velocity? Did you know that… - change in velocity over time is called acceleration. - negative acceleration is deceleration.

Activity 4What to do: 1. Make 2 similar push carts using cardboard boxes with wheels as shown in the figure. 2. Place these carts side by side. 3. Put some stones in push cart A. Leave push cart B empty. 4. Push the two carts with the same force with your left and right fore finger to different directions. a. Which cart moved faster? Why? b. Which cart can change direction easily? Why? c. Which cart can accelerate or change velocity easily? Why? 5. What factors affect acceleration? 6. Study these illustrations. One truck is loaded while the other is empty.  Which truck moves faster? Why?  Which truck moves slowly? Why?  Which truck can change speed slowly? Change direction slowly?  Which will accelerate more slowly?  What factors affect acceleration?  How can the problem of acceleration be solved in loaded trucks?  What will you do to make a smaller bike win over a bigger bike?

more mass – less acceleration less mass – more acceleration truck – less acceleration bicycle – more acceleration more mass + more force – more acceleration more force - more accelerationActivity 5What you need: 2 similar marbles 2 30 - cm piece of cardboard 6 books some sand a plastic coverWhat to do: 1. Pile 6 books on top of each other. 2. Cover one board with a plastic cover or any smooth cover. 3. Scatter a glass of sand over the other board. 4. Place side by side one end of the 2 boards on the edge of the books. 5. Roll the marbles on each of the board at the same time?  In which board did the marble roll faster?  What outside force helped the marble to roll faster?  What was lessened because of the smooth surface?  Which board did the marble roll slowly?  What outside force helped the marble roll slowly?  Describe the outside force that caused the marble to roll slowly? 6. A force made the marble rolled down. An opposing or opposite force is also acting on the marble.

Did you know that…  friction is an external force that affects the movement of bodies.  friction can be lessened by using wheels, lubricants and smooth surfaces.  friction can be increased by making surfaces rough, like the grooves of a tire.I LEARNED THAT:  Speed is the distance traveled over a certain period of time.  Velocity is the speed of a moving object in specified direction.  Velocity changes when there is change in speed, change in direction or change in both speed and direction.  Acceleration is the change in velocity over time. Deceleration is negative acceleration.  Acceleration is affected by the mass of a body and the amount of force applied to it.  Friction is the force that opposes the motion of an object.  Friction is the force that brings an object to rest.  When objects are in contact with each other, friction acts in the direction opposite to the motion of the moving body. The moving body slows down and finally stops.

Apply It Find out how speed and velocity are related. Describe moving bodies with constant velocity. How can friction be of help to you? Why are wheels round?* Test YourselfA. Match column A with the description in column B. Write the letter of the correct answer on your test notebook.AB1. speed A. brings an object to rest2. friction B. speed of a moving objects towards a direction3. acceleration C. less mass4. greater acceleration D. change in velocity5. velocity E. tells how fast you runB. Explain why is it easy and fast to move in an ice rink.

Key to CorrectionTry to RecallExploration Time Activity 1 Activity 2 Activity 3 Activity 4 Activity 5Apply itTest Yourself 1. E 2. A 3. D 4. C 5. B