Grade 4, Unit P.1, Sound SOUND

Transcription

1 SOUND 1

2 By the end of this unit you should: Know that sound is a vibration. Know that sounds can travel through solids, liquids and gases. Know that sound can vary in loudness and in pitch. Know that we hear sounds that travel to our ears, and we are not able to hear all the sounds. Know the importance of having two ears. Know what noise is. Know what Echo is. 2

3 science standard:15.2 لاي هللا ذؼا :- ( ال ذ م ف ا ١ ظ ه ت ػ إ ا غ غ ا ث ص ش ا ف ؤ اد و ه و ا ػ غ ؤ ال ال) )سورة اإلسراء: آية 36( What kind of sounds have you heard today? If you live in town, you may have heard Cars And buses. If you are in the countryside, you may have heard sheep or cows. ا االص اخ ا ر ع ؼر ا ا ١ ارا و د ذغى ف ذ ٠ ح,فا ه خع غ اص اخ ا غ ١ اساخ ا ثاصاخ, ا و د ذغى ا مش ٠ ح فا ه ذغ غ اص اخ ا خشاف االتماس. A sound is made when an object vibrates. When something vibrates it moves forward and backward. Usually you can not see an object vibrating when it makes a sound because it is moving too quickly. ٠ غ غ ا ص خ ػ ذ ا ٠ رزتزب ا عغ, ػ ذ ا ٠ رزتزب ا عغ فا ٠ رؽشن ا اال ا ا ا خ ف, ػادج ال غرط ١ غ ا ش ا زتزتاخ ال ا ذرؽشن تغشػح. 3

4 Sound is made when an object vibrates. ٠ شأا ص خ ػ ذ ا ٠ رزتزب ا عغ Vibration when an object moves forward and backward very quickly. ا زتزتاخ ػ ذ ا ٠ رؽشن ا عغ ا اال ا ا ا خ ف تغشػح You can see and feel the vibration from a tuning fork when it makes a sound. ذغرط ١ غ ا ذش ا ذشؼش تا زتزتاخ ا ش وح ا ش ا ح ػ ذ ا ذ شئ ا ص خ. To make the tuning fork work you need to bang the prongs against a table and then stand the fork on the hard surface. اغشق ش وح س ا ح ش شثر ا ػ عطػ ص ة. If you look closely you can see the prongs vibrating very quickly. إرا ظشخ إ ا ش وح لشب ع ف ذالؼظ فشػ ١ ا ذرؽشوا If you touch the prongs lightly you can feel the vibrations. إرا غد فشػ ١ ا فغ ف ذشؼش تا زتزتاخ. You can see the vibrations if you put rice on a drum, and then hit the skin. 4

5 ذغرط ١ غ ا ذش ا زتزتاخ ارا ظؼد االسص ػ ا طث ػ ذ ظشت ا. Key Words: ا ص خ Sound ا زتزتاخ Vibration Tuning fork ا ش وح ا ش ا ح ا طث Drum Key Ideas ا ص خ رتزتاخ Sound is a vibration Vibration is when an object moves forward and backward very quickly. ا زتزتاخ ػ ذ ا ٠ رؽشن ا عغ إ األ ا ا ا خ ف تغشػح Key Questions و ١ غ ذ شئ االص اخ made? 1. How are sounds ا ا زتزتاخ vibration? 2. What is Science standard: 15.3 ٠ رم ا ص خ ػ غش ٠ ك ا ظاخ Sound travels in waves Sound moves through the air in waves. ا ص خ ٠ رم ف ا اء ػ غش ٠ ك األ اض. 5

6 We normally think of sound waves as traveling through the air, but the truth is that they can travel through solids, liquids and gases. ؼرمذ ػادج ا اال اض ا ص ذ ١ ح ذ ركي ػ غش ٠ ك ا اء فمػ, ى ا ذ رم ػ غش ٠ ك ا ص ة ا غائ Sound waves travel by making particles vibrate. ا غاص ا ٠ عا. ظاخ ا ص خ ذ رم ػ غش ٠ ك ظؼ رساخ ا ادج ذ رض ا ص خ ٠ رم ػ غش ٠ ك ا اء Sound travels though air When you talk to a friend, the vibration travels through air to ػ ذ ا ذرى, ا ظاخ ذ رم خالي ا اء ؼر ذص ار ص ١ ه ears. reach your friend s The vibrations make the air around the instr The drum skin makes the air around it vibrate. ا زتزتاخ ذعؼ ا اء ؼ ي االداج رض ا ٠ عا The vibrations made by the guitar strings, drum skin and triangle اال رضاصاخ ا ر ذ شئ خ ١ غ ايل ١ صاس, ظ ذ ا طث ا ص س vibrates. make the air ذعؼ ا اء ٠ رض 6

7 When these vibrations reach our ears, we hear them as sounds. ا ص خ ٠ رم ػ غش ٠ ك ا اء Sound travels though water Sound travels in water, next time you go to swimming try to talk to your friend under the water. ا ص خ ٠ ذم ػ غش ٠ ك ا اء, ف ا شج ا ماد ح ػ ذ ر اته غثاؼح ؼا ي ا ذرى غ ص ١ ه ذؽد ا ا ء. ا ص خ ٠ رم خالي ا اد ا ص ثح Sound travels though solids If you are sitting at a table place your ear on the table. Stretch out your arm and tap the table very gently with one finger. Even though this tap is a very quiet sound, you can hear it clearly as the sound vibrations travel through the table and enter your ear. ظغ س عه ػ ا طا ح ا مش ػ ا طا ح تأصاتؼه ع ف ذغ غ ص خ ا مش ت ظ غ ال رتزتاخ ا ص خ ذ رم خالي ا طا ح إ ر ه. 7

8 Project Here is something you can try at home All you need is a length of string and two plastic cups. Try it with different types of strings. Grade 4, Unit P.1, Sound Key Words: Waves ذ ظاخ Travel ٠ رم Solid ص ة Liquid عائ Gas غاص Key Ideas Sounds travel through solids, liquids and gases. ا ص خ ٠ رم ػ غش ٠ ك ا اد ا ص ثح ا غائ ح ا غاصاخ Key Questions و ١ ف ٠ ى ا ٠ رم ا ص خ through? 1. What can sound travel ػ ذ ا ذغرخذ ا ذسعح ا صافشج, و ١ ف ٠ رم ا ص خ ا whistle..2 The teacher blows the ارا ا طالب How does the sound of whistle reach the children's ears? 8

9 Science standard: 15.1 ا ص خ شذج Loudness Changing the loudness of a sound is like turning the volume button on the television up or down. You do not change the type of sound, just whether you can hear it easily or not. ذغ ١ ش اسذفاع ا خفاض ا ص خ ٠ شث ذؽش ٠ ه ؤشش ا ص خ ف ا ر فاص ا اػ اعف. You can make the sound of a drum louder by striking it harder. ذغرط ١ غ ا ذعؼ ص خ ا طث اػ ارا ظشتر تم ج. In that way, you give it more energy and the vibrations are bigger. If you strike it very gently, you get small vibrations and a very quiet sound. ت ز ا طش ٠ مح د ذثزي غالح اوثش تا را ذى اال رضاصاخ اوثش. ػ ذ ظشت ت طف فا اال رضاصاخ ذى صغ ١ شج ا ص خ اظؼف. شذج ا ص خ: ا خاص ١ ح ا ر ذ ١ ض ت ا األر األص اخ ؼ ١ س ا م ج ا عؼف, خعرط ١ غ ذم ي زا ص خ ل زا ص خ ظؼ ١ ف. 9

10 Sounds of different volumes can be produced when this drum is hit: a) gently or b) hard. ا طشق ا م طث ح ٠ ؼط ص ذا ل ٠ ا ا طشق ا خف ١ ف ٠ ؼط ص ذا ظؼ ١ فا. Look at the pictures above: Sounds of different volumes make waves of different heights. Sound A is louder than B. ؼعا ا ص خ ا خر فح ذص غ ظاخ بعؼح ا رضاصاخ خر فح ا ص خ A ػ ا ص خ B ا ص خ ا م ٠ صؽث عؼح ا رضاصج وث ١ شج ا ص خ ا طػ ١ ف ٠ صؽث عؼح ا رضاصج صغ ١ شج. ذمذ ؼ شذج ا ص خ ذؼر ذ ػ عؼح اال رضاصاخ. 10

11 Sounds can be quiet or loud depending how close to the sources of the sounds you are. ا ص خ ى ٠ ى اد ء ػا ػ ؼغة لشته صذس ا ص خ. دسظح ا ص خ Pitch Any sound that you hear as a tone is made of regular, evenly ص خ غ ؼ و غ ح ف األص ظح. molecules. spaced waves of air These differences in the pitch of the sound are caused by different spacing in the waves; the closer together the waves are, the higher the frequency, the higher the tone sounds. االخرالف ف دسظح ا ص خ ٠ شظغ إ ا غافح ت ١ ا ظاخ, و ا وا د ا ظاخ رماستح و ا صاد ا رشدد و ا وا د غ ح ا ص خ ػا ١ ح. 11

12 دسظح ا ص خ: ا خاص ١ ح ا ر ذ ١ ض ت ا األر األص اخ ؼ ١ س ا ؽذج ا غ ظح. ا ص خ ا ؽاد وصش ذشددا ال ا ص خ ا غ ١ ظ. When plucked, a short string gives a higher-pitched sound than a ا ذش ا مص ١ ش ٠ صذس ا ص خ وصش ؼذج ) دسظح ػ ( ا ذش ا ط ٠ ال ذشدد ػ string. long The thick strings make a low pitched sound, but the thin strings make a high pitched sound. األ ذاس ا غ ١ ىح ا ذشدد )دسظح ص خ( ل ١ ح األ ذاس ا شف ١ ؼح ا ذشدد )دسظح ص خ( ػا ١ ح. When banged, a tight drum skin gives a higher-pitched sound than a loose drum skin. إرا وا ظ ذ ا طث ح شذ د فئ ا ذصذس ص ذا وصش ؼذج ) دسظح ػ ( ا ع ذ ا شذخ ال ا ذشدد ػ. A small instrument vibrates very quickly (a small drum or a thin guitar string) it has a high pitch. األالخ ا صغ ١ شج ذرزتزب تغشػح وث ١ شج زا ا غ ح ػا ١ ح A big instrument vibrates very slowly and gives a low note. It األالخ ا ىث ١ شج ذرزتزب تثػء زا ذؼط غ ح خفعح pitch. has a low 12

13 Project: Using different sizes of elastics bands and try to investigate the relationship between the size and the pitch. Key Words: Loudness ػ ا ص خ Volume ؼع ا ص خ Pitch ؼذج ا ص خ Key Ideas Sounds have both pitch and volume. األص اخ ا ؼع غ ح The volume of Sounds can be low or ػ ا ص خ لذ ٠ ى شذفغ ا خفط loud. The pitch of a sound depends on the غ ح ا ص خ ذؼر ذ ػ ؼع االداج size. instrument Key Questions 1. How can you make a louder sound on an instrument? و ١ ف ٠ ى ذ رط ص خ ػا األداج 2. Why women s voice is different from men s voice? ارا ٠ خر ف ص خ ا ش ج ػ ص خ ا شظ 3. Which one of these pictures shows the louder sound? A B 13

14 Science standard: 15.4 We hear sounds when the vibrations travel from the objects to our غ غ االص اخ ػ ذ ا ذ رم ا زتزتاخ االظغا ا ارا ا ears. ذؼ و ١ ف غ غ االص اخ sounds? Do you know how we hear the Sounds go into our ears and make our eardrums move. االص اخ ذ رم ا ارا ا ذعؼ غث ح االر ذرؽشن This tells our brain that we have heard a sound. زا ٠ ث غ ا خ ا ا ع ؼ ا ص ذا ال It is important never to poke things in our ears, because we can ا ا ال ذخ ا ش ء ف ارا ا ال ر ه لذ ٠ ؤر ٠ ا تغ ح easily. hurt them Our ears tell us where the sound is coming from. االر ا ذخثش ا ا ٠ صذس ا ص خ If a friend who is standing to your left calls your name. The sound reaches your left ear first then it reaches your right ear. ارا اد صذ ٠ مه ا ز ٠ مف ػ ا ع ح ا ١ غش ه تاع ه, فا ا ص خ ٠ ص ار ه ا ١ غش ا ال ش ار ه ا ١ 14

15 The brain can tell you that the sound is louder to the left ear and it tells your head to turn left to see your friend. Having two ears helps you know where the sound is coming from, even if you were blindfolded. ا خ ٠ غرط ١ غ ا ٠ خثشن ا ا ص خ اػ ا ع ح ا ١ غش ٠ خثشن ا ذرع تشاعه ع ح ا ١ غش رش صذ ٠ مه. Having two ears helps us to tell where the sound is coming from. ظ د ار ١ ٠ غاػذن ؼشفح ا ٠ صذس ا ص خ Sounds we can not hear Many animals have better hearing than we do. Dogs have very sensitive hearing; they can hear higher pitched sounds than we can. وص ١ ش ا ؽ ١ ا اخ ذر رغ تؽاعح ع غ ال اال غا, ا ىالب ا ؼاعح ع غ ل ٠ ح, ف ذغرط ١ غ ا ذغ غ ا غ اخ ا ؼا ١ ح االص اخ اوصش اال غا. The dog owners have a whistle that only dogs can hear. ا ى ا ىالب ذ ٠ صفاسج ٠ غرط ١ غ فمػ ا ىالب ع اػ ا. Elephants can hear lower pitched sounds that we can not ا ف ١ ٠ غرط ١ غ ع اع ا غ اخ ا خفعح ظذا ال ا ر ال غرط ١ غ ع اػ ا ؽ hear. 15

16 There are some sounds that are either too high or too low for us to hear. ان تؼط االص اخ ا ر لذ ذى راخ ذشدداخ ػا ١ ح ا خفعح ظذا ال فال غرط ١ غ ا غ ؼ ا Key Words: ا غ غ Hearing Eardrum غث ح االر Whistle صفاسج Key Ideas We hear sounds when they travel to our ears. غرط ١ غ ع اع االص اخ ػ ذ ا ذ رم ا ارا ا Having two ears helps us tell where sound is coming from. ظ د ار ا ٠ غاػذ ا ػ ا ؼشف ا ٠ صذس ا ص خ There are sounds that are either too low or too high for us to hear. ان تؼط االص اخ ا ر لذ ذى راخ غ اخ ػا ١ ح ا خفعح ظذا ال فال غرط ١ غ ا غ ؼ ا Key Questions و ١ ف غ غ االص اخ sounds? 1. How do we hear ارا ال ٠ عة ا ذخ ears? 2. Why must we never poke things in our االش ١ اء ا ارا ا غرط ١ غ ع اع و االص اخ فغش Explain! 3. Can we hear all the sounds? 16

17 Science standard: 15.5 Noise can almost be any sort of sound, but the word is especially applied to unwanted or unpleasant sounds. The sounds of traffic and construction work in the city are noise. The louder they are, the worse the noise. اص اخ ا ؽشوح ا ش س ٠ ح اػ اي ا ث اء اصػاض Even your favorite music can be noise if it distracts you while you are studying for examination. ؼر ا ع ١ مره ا فع ح قد ذى اصػاض ارا ا ره ا د ذذسط ال رؽا ه. 17

18 Sound counts as noise if it is so loud that it becomes painful to hear, or even damages your sense of hearing. االص اخ ذؼذ اصػاظا ارا وا د ػا ١ ح ا ؤ ح غ غ, ا ذذ ش ؼاعح ا غ غ ذ ٠ ه Very loud sounds can be dangerous as they can damage your ears. In order to protect their ears from noise, workers wear earmuffs when they are working with loud machinery. ؽ ا ٠ ح االر االصػاض, ا ؼ اي ٠ شذذ ال ١ اخ الر ػ ذ ػ تاالالخ راخ االص اخ ا ؼا ١ ح. Sound travels through materials better than others, so the material for earmuffs is chosen carefully to keep the sound out. 18

19 Activity Which material would be the best to make earmuffs? Some children decide to investigate which material would be the best for making earmuffs to stop sound reaching their ears. The children planned an investigation for testing five different materials as earmuffs: cotton wool, paper towel, carpet, plastic bag and bubble wrap. They made a pair of earmuffs using a hair band and rings of cardboard. The different materials could be Stuck to the cardboard rings. The children chose one person to wear the earmuffs. This person had to walk away from a buzzer until she could not hear the noise any longer. The distance between the person and the buzzer was measured. The children did this test using each different material in the earmuffs. Which materials made the best earmuffs? 19

20 Key Words: االصػاض Noise Damage ذذ ١ ش Earmuffs غطاء االر Key Ideas Noise is an Unpleasant or very loud sound. االصػاض ص خ غ ١ ش شغ ب ت, ا ص خ ػا ظذا ال Loud sounds can damage the ears. االص اخ ا شذفؼح ٠ ى ا ذؤر االر People who work where there is a lot of noise wear earmuffs to protect their ears. االشخاص ا ز ٠ ٠ ؼ ف ا ىا ا ر ف ١ ا اصػاض ٠ ثغ ال ١ اخ الر ؽ ا ٠ ح ارا Key Questions اؼزف ا ى ح ا خطأ. sentence 1. Cross out the wrong word in each (Very loud/quiet) sounds can be dangerous as they can damage your ears. األص اخ )ا صاخثح - ا ادئح( خط ١ شج أل ا ذذ ش األر Noise is an (pleasant /unpleasant) sound ا ع ظاء ص خ ) غ / صاخة(. و ١ ف ٠ ى ا ٠ رذ ش ا غ غ ذ ٠ ا damaged?.2 How can hearing be... 20

21 Science standard: 15.6 Did you throw a rubber ball on a brick wall and it bounced back? عثك ا س ١ د وشج طاغ ١ ح ؽ ا عذاس ػادج ا ١ ه Sound bounces too, sound that bounces off something before reaching a listener is called echo. ا ص خ ٠ شذذ ا ٠ عا ال, ا ص خ ا ز ٠ شذذ ػ ش ء لث ا ٠ ص ا ا غر غ ٠ غ صذ ا ص خ. Echo: A sound that bounces off a surface صذ ا ص خ: ا ص خ ا غ ع تؼذ ا ؼىاع ػ ؼاظض ؼ ١. The sound that travels directly reaches the listener first then the echo is heard ; that is because the sound that travels directly has less distance to travel and takes less time to travel to our Ears. ا ص خ ا ز ٠ رم ثاششج ٠ غ غ ا ال ش ٠ غ غ صذ ا ص خ, زا ال ا ص خ ا ز ٠ رم ثاششج ٠ مطغ غافح الصش تا را ٠ ؽراض لد ال ١ ص الر. 21

22 Sailors can use echoes to find out the depth of the sea ٠ ى اعرخذا صذ ا ص خ ف ص ١ ذ األع ان ل ١ اط ػ ك ١ ا ا ثؽاس. وز ه ٠ ى اعرخذا صذ ا ص خ ف ا ىشف ػ ؼص اخ ا ى ا شاسج ذفر ١ ر ا. Let's measure: Use a ruler and see for yourself. Have two students standing one facing each other while talking; then ask one of the students to move for some distances and measure the distance for each move. You should record the final distance where one of them could not hear the other. عاي اؼذ ا طالب ٠ رؽشن غافح تؼ ١ ذ ػ ص ١ ح تؽ ١ س ال ٠ غرط ١ غ ع اع األخش ش ل تم ١ اط ذ ه ا غافح..ا غافح ذغا The distance is 22

23 Do the same steps for this activity, but ask one student to stand in front of the wall while talking and to move for a certain distance until an echo will be heard. Don't forget to measure the distance وشس فظ ا خط اخ عاي ؼذ ا طالب ٠ مف ا ؼائػ ٠ رؽذز ش ذؽشن time. every ٠ رؽذز ؼر ٠ ر ع اع صذ ص ذ ال ذ غ ل ١ اط ا غافح و شج..ا غافح ذغا The distance is The longer the distance the sound needs to travel; the more time it needs to reach your ears. و ا وا د ا غافح ا ر ٠ مطؼ ا ا ص خ اغ ي, و ا وا اي لد ا ز ٠ ؽراظ ص ي ألر غ ي. Key Words: صذ ا ص خ Echo Bounces off ٠ شذذ Key idea When sound bounces off a surface we have echo. ػ ذ ا ٠ شذذ ا ص خ ػ ا غطػ فا ا صذ ٠ ؽذز Key Questions ا صذ ا ص خ echo? 1. What is. ػػ شاي ٠ ى ف ١ ا صذ ف ١ ذ helpful: 2. Give one situation where echo is.. Project Design an experiment to explain why the sound that travels directly reaches the listener first then the echo is heard. 23