Alat Peraga IPA SD

Penyajian demonstrasi hendaknya mampu menimbulkan minat; menggunakan bahan- bahan sederhana; gunakan semua pintu gerbang; kaitkan dengan contoh dan ikat dengan kegembiraan dan antusias.

4. Alat Peraga IPA SD

THE POWER OF FALLING WATER Make a simple water turbine to produce ‘hydro’ power INTRODUCTION [METHOD] Many of the worlds most powerful machines are driven by the power of water. In the days of our ancestors, falling water was used to drive water wheels to produce power for grinding grain. These days many natural forms of running water, like rivers, are used to drive very large water turbines to form powerful hydroelectric power stations. In the following science experiment we will build a simple water turbine to explain the principle of how hydroelectric power is generated: STUFF YOU NEED [MATERIALS]  PLASTIC BOTTLE  WINE CORK  KNITTING NEEDLE  NAIL  COAT HANGER WIRE  FOUNTAIN PEN NIBS 5 HOW TO PROCEED [PROCEDURE] 1. Start off by pushing a thin long knitting needle through the centre of a wine bottle cork, so that the cork is positioned more or less in the middle of the needle. 2. Ask you parents for some old fountain pens and use the nibs to act as water scoops by sticking them into the cork at even spacings and at right angles from the cork base. Use at least 5 nibs to make sure the water wheel is driven properly by the water stream. This will form your turbine rotor. 3. Bend the stiff wire from an old coat hanger to make a stand and a cradle for the turbine rotor. Make sure the rotor is able to turn freely on the cradle. 4. Next, press a nail trough the side, and close to the bottom, of a plastic bottle with water. This will create a constant stream of running water and will be the source of power to drive your water turbine. 5. Place the bottle a little higher than the turbine for the water stream to hit the rotors at right angles and the wheel will start to spin. This rotational energy is often used in real life to drive the shaft of an electric generator. FOOD FUNGUS Create a colourful fungus garden INTRODUCTION [METHOD] Microorganisms, also called fungi, live around us and we come into contact with it every day. Microorganisms are microscopically small and in most instances we do not even know that they are there. Fungus keeps reproducing, and can also grow very large in favourable conditions such as on rotting food. We know this as mold. Many different types of fungi exist around us, lets see how many types we can grow in the following science experiment: STUFF YOU NEED [MATERIALS]  LARGE GLASS JAR 6  TAP WATER  BANANA  CHEESE  BREAD HOW TO PROCEED [PROCEDURE] 1. Place a few food items such as bananas, cheese and bread in a large glass jar. Fill the jar with food only about 13rd full with these foods. 2. Sprinkle a few spoons of water over the food in the jar to create a nice and moist environment for the fungi to grow in. 3. Put the lid on the jar and leave it in a cool dry place, out of direct sunlight where it will not be disturbed. 4. After a few days you will notice the fungi that grow on the food to create a colourful fungus garden BIO-JAR Build your own biosphere INTRODUCTION [METHOD] A biosphere, also called an ecospheres is a mostly closed ecosystem, of a specific size, that contains a mix of plants and animals that is completely self-sufficient. The only input to a biosphere is energy or light. All other materials needed by the biosphere such as water, nutrients, oxygen, nitrogen and carbon dioxide, amongst others, are sealed within it and recycled through the process of life, death, and decay. Planet earth is also a biosphere, even 7 though it is much, much larger than the biosphere we will be creating in the following science experiment: STUFF YOU NEED [MATERIALS]  341 HOW TO PROCEED [PROCEDURE] 1. Use small pebbles to lay out the bottom of a very large glass jar. Use enough pebbles to completely cover the entire bottom of the jar. 2. Obtain some horticultural charcoal from your local garden supply store and sprinkle some of it over the pebbles to create a thin layer of charcoal. 3. Using scissors, cut a circular shape out of a piece of cloth the same diameter as the inside of the jar. Place it inside the glass jar to cover the layer of charcoal. 4. Now, use a large bowl and spoon to mix together the following items, all available from your local garden supply store: 1 cup potting soil, ½ cup peat moss, ½ cup vermiculite, ½ cup compost and ¼ cup aquarium sand. 5. Place a layer of the mixture in step 4 on top of the cloth that was placed over the charcoal and add some water to moisten the mix. 6. Plant a small bean plant or similar into the soil, and add some more soil as necessary to fix the plant securely in the ground. Also add some more water. 7. Screw the lid tightly onto the jar and seal the sides of the lid with duct tape if necessary. 8. Place your biosphere glass jar somewhere where it will receive enough indirect sunlight. Observe your biosphere daily and record any changes over two weeks. See how long your biosphere lasts 8 RELAY REPLAY Build a relay to remotely control other electrical circuits INTRODUCTION [METHOD] An electrical relay is a switch which is under the control of another circuit. A classic relay consists of an electromagnet, used to control switches that may either open or close another electrical circuit. There are many reasons for using a relay, but mostly in situations where a small current flow is used to switch on a large current flow, or high voltage which also makes the system safer to use. A classic example of an electrical relay is the system used to start a car. When someone turns an ignition key, the ignition does not interact directly with the car battery. Instead, it activates an electrical relay which passes the signal on so that the car can start. In this science experiment, use a relay to control the activation of two LEDs by opening or closing a circuit to control another: STUFF YOU NEED [MATERIALS]  INSULATED COPPER WIRE  2x 9-VOLT BATTERIES  2x 9-VOLT LED’S  SINGLE THROW SWITCH  DOUBLE THROW RELAY  WIRE CUTTERS  ADULT HELPER HOW TO PROCEED [PROCEDURE] 9 1. Assemble the first circuit red as per the diagram above by connecting a 9-Volt battery to a switch and a relay in series with insulated copper wires and alligator clips. 2. Assemble the second circuit blue as per the diagram above by now connecting two LEDs to the relay in series with another battery in between them connected to the relay in parallel. 3. Turn on the switch red circuit and notice which of the LEDs lights up. When the switch is turned off, the other LED will light up ON OR OFF Build and learn about an ‘AND’ and ‘OR’ computer logic circuit INTRODUCTION [METHOD] The first complex electronic appliances were all made up of various single components such as tubes, capacitors, coils and resistors and transistors. Today integrated circuits may contain thousands of these single components built into a much smaller single unit that can perform a handful of operations. Such circuits can include storage of data flip-flops and gates. A logic gate is a circuit that will allow passage of a signal under certain conditions only. The two most common computer logic gates are the AND and the OR gates. Use toggle switches to represent the concept of AND and OR computer logic gates in the following science experiment: STUFF YOU NEED [MATERIALS]  SMALL ELECTRONIC BREADBOARD  INSULATED SOLID HOOK-UP WIRE  4x SINGLE THROW SWITCHES  2x LED LIGHTS  6-VOLT BATTERY  SOLDERING IRON WIRE  WIRE CUTTERS  ADULT HELPER 10 HOW TO PROCEED [PROCEDURE] 1. Obtain a small piece of electronic breadboard, two 6 volt LED lights and four single pole single throw switches from an electronics hobby store. 2. Working with a soldering iron is dangerous Ask your parents or an adult to help you with the soldering iron to connect all the components to the breadboard to form the two circuits as in the diagram above the polarity of all the components in this experiment is important, make sure you connect the + and -terminals of each correctly. 3. Construct logic circuit 1 so that the two toggle switches are placed in series representing the AND gate. Only if both switches in this circuit is placed in the on position, the LED will light. 4. Construct logic circuit 2 so that the two switches are placed in parallel. If either the 1st or 2nd switch is placed in the on position, the LED will light 5. Make a chart with all the possible combinations of onoff positions and the switches with the AND and OR logic tables. Try each switch combination by placing the switches in various on and off positions and take note in which combinations the LEDs are lit or not ELECTRO-MAGNETIC BOUNCER Make a wire spring jump up and down with electro- magnetism INTRODUCTION [METHOD] In this science experiment, you will use the power of electric current to make a thin wire coil behave in a mysterious way. When current is passed along a conductor, the conductor 11 behaves like a magnet, especially if the conductor or wire is formed in a coil. A wire twisted along the base of another object to form a coil, is called an electro-magnet: TUFF YOU NEED [MATERIALS]  9-VOLT BATTERY  THIN COPPER WIRE INSULATED WIRE  STYROFOAM BALL  SMALL, FLAT BALL  SALT  PENCIL  BOOKS HOW TO PROCEED [PROCEDURE] 1. Twist a thin copper wire around the base of a pencil to form a coil and slip it off the pencil. 2. Push a copper nail through the centre of a Styrofoam ball so the both ends stick out about 10-20mm. Tie the one end of the thin copper wire to the head of the copper nail. 3. Push the sharp end of a long pencil in the side of the Styrofoam ball so that it is perpendicular to the nail. 4. Fix the other end of the pencil in position on a stack of books so that the thin copper wire coil is suspended from the nail in the Styrofoam ball, about 100-150mm away from the books. 12 5. Stretch out the wire coil suspended from the nail in the ball so that it becomes a kind of a spring with the other end suspended just above the surface of the table. 6. Fill a small, flat bowl with supersaturated warm salt water, and place it underneath the coil so that the bottom tip of the coil is just below the surface of the salt water. 7. Ask your parents or an adult to help you strip away about 20mm of insulation of the ends of two insulated wires of about 400mm in length each. 8. Connect the end of each of the insulated wires to the terminals of a 9-volt battery and connect one of the free ends of the insulated wire to the nail sticking out at the top of the Styrofoam ball. Now, place the other free end of insulated wire into the salt water solution in the bowl and see how the copper spring bounces on the water frantically ASTROORDINARY Make a simple astrolabe to measure the altitude of objects in the sky INTRODUCTION [METHOD] An astrolabe is a device used for measuring altitude, including the height of objects in the sky. The name has its origins from the Greek words astron and lambanien meaning the one who catches the heavenly bodies. Creating your own astrolabe can be quick and easy, as you will see in the following science experiment: STUFF YOU NEED [MATERIALS]  THICK CARDBOARD  COLOURED STRING  DRINKING STRAW  WASHER WEIGHT  STICKY TAPE  SCISSORS  PROTRACTOR 13 HOW TO PROCEED [PROCEDURE] 1. On a piece of thick, white cardboard, use a pencil and the outline of a round object to draw a quarter circle with a radius of about 150mm. 2. Use a protractor to divide the rounded edge into 9 equal segments, representing 10 degree increments from 0 degrees to 90 degrees, as in the diagram above. 3. Label the degree markings on the astrolabe with a pen from 0 degrees to 90 degrees from both sides as in the drawing above. 4. Cut the astrolabe out with scissors and make a small hole near the corner. 5. Fix a drinking straw to one of the flat sides of the astrolabe with sticky tape, and cut the sides of the drinking straw short to protrude only slightly past either side of the quarter circle. 6. Pass a piece of coloured string through the hole in the corner and either tie the string in a knot at the back of the cardboard, or tape it there. 7. Tie the small washer or other weight to the opposite end of the string as shown. 8. To use the astrolabe to take a measurement, look at the top of a tall object through the straw, and have someone read the altitude in degrees from the side of the astrolabe. The point where the string crosses the scale is the proper measurement. 9. Now, use your astrolabe to measure the altitude of the sun by holding it so that the straw points in the direction of the Sun. Do not look directly into the sun as it might damage your eyes 10. Aim the straw so that you see the shadow of the straw on your hand. Adjust the straw position slightly until a small circle of light forms on your hand. The straw is now pointing directly at the Sun. 14 11. Ask someone to read the Suns altitude in degrees where the string crosses the scale. Take note of the time of day the reading was made and record your results. 12. Take altitude readings every two weeks at the same time of day for a few months, and notice the change in altitude over time. Make a chart to record your findings HOW IS WATER MADE? Use electrolysis to find out what substances is water made of INTRODUCTION [METHOD] All chemical substances or elements can be described in a shorthand method, for example H ₂O for water, or CO₂ for carbon dioxide. Chemists often use this method of describing all the chemical substances, better known as a substances chemical formula. A chart known as the periodic table contains all the chemical elements according to their atomic number, weight, density and more. For instance Hydrogens formula is H and oxygens formula is O and waters chemical formula is known as H ₂O. This shows us that water is made up of 1 part oxygen and two parts hydrogen. Prove this is true in the following exciting science experiment – the electrolysis of water: STUFF YOU NEED [MATERIALS]  BOWL OF WATER  CARBON RODS  LONG MATCH  9V BATTERY  2x TEST TUBES HOW TO PROCEED [PROCEDURE] 15 1. Use a 9-volt battery for this experiment. Please do not use any other means of electricity as this could be very dangerous 2. Obtain two small carbon rods the electrodes from your hardware store and connect a wire to each of them. Then, connect the other ends of the wires to the positive and negative terminals of the battery. 3. Place the electrodes in glass test tubes filled with water as in the diagram above and place these in the bowl of water. The two carbon electrodes will carry the electric current into and out of the water in the bowl. 4. Once the battery is connected and all items have been set up as per the instructions, you will notice that bubbles of gas will start to rise from the carbon rods or electrodes. 5. The gas will collect in the top of the tubes and after a while you will notice that the one tube contains twice as much gas as the other The hydrogen. 6. Ask your parents or an adult to help you test these gasses in the following matter: Take the first test tube out of the water and immediately drop a lighted match into it – you will hear a loud pop as the gas inside burns up rapidly indicating it is hydrogen. Do the same with the second test tube but drop a glowing, not a burning match inside. It will burst into flames indicating it is oxygen gas. CANDLE IN THE WIND Re-light a candle by igniting the smoke with a INTRODUCTION [METHOD] Amaze your friends with your stunning candle act. You can light the candle without touching the wick in the following science experiment: STUFF YOU NEED [MATERIALS]  CANDLE  MATCHES  ADULT HELPER 16 HOW TO PROCEED [PROCEDURE] 1. Ask your parents or an adult to light up a candle and place it in a saucer on a table. 2. Now, blow the candle out and then watch the smoke drift upwards into the air. 3. Quickly strike up a match, but this time dont light the wick, hold the match near the top of the smoke stream. 4. The smoke will instantly catch fire and burn downward until it reaches the wick itself and then — your candle is once again lit FALLING TIME Calculate the viscosity factor of various liquids INTRODUCTION [METHOD] All fluids, liquids and gases, show signs of viscosity to some degree. Viscosity may be thought of as the friction within a fluid, similar to the friction between two solids that resists the motion of one over the other. Friction makes it possible for an object to acceleration relative to another object, such as the friction between the wheels of a car on a highway. Measure the viscosity of various liquids by calculating the average time a round solid object takes to fall through the liquid to the bottom of a bottle in the following science experiment: STUFF YOU NEED [MATERIALS]  GLASS BOTTLES  SMALL BALL BEARING 17  STOP WATCH  COOKING OIL  BABY OIL  GOLDEN SYRUP  MAGIC MARKER HOW TO PROCEED [PROCEDURE] 1. Pour a small glass bottle about ¾ full of cooking oil and mark the level of the liquid with a magic marker. This mark will be used when testing the other liquids so that a constant level is used and the liquids can be properly compared. 2. Drop a small ball bearing about 10mm diameter into the liquid in the bottle and use a stopwatch to time the number of seconds it takes for the ball bearing to fall to the bottom of the bottle. 3. Do the procedure two more times, and each time record the results to obtain the average falling time for each of the liquids tested. 4. Repeat steps 1 to 3 for the baby oil, syrup and other substances you might want to test. 5. Draw up a data chart to compare the viscosity of various liquid substances. GONE WITH THE WIND 18 Observe how a stream of air can follow a curved surface INTRODUCTION [METHOD] Air pressure is a very powerful force. Let us prove how powerful air pressure can be with the following simple science experiment: STUFF YOU NEED [MATERIALS]  2L PLASTIC BOTTLE  CANDLE  MATCHES  ADULT HELPER HOW TO PROCEED [PROCEDURE] 1. Place a large plastic water bottle on a table and place a candle in a saucer next to the bottle about 8-12cm away. 2. Ask your parents or an adult to light the candle. 3. Now, blow hard on the side of the bottle that faces away from the lit candle. 4. The candle will be extinguished even though the candle is not in the direct stream of air flowing from the other side of the bottle SIPHON SUCTION 19 Find out how a simple siphon works INTRODUCTION [METHOD] Even though air is light, there is so much of it that air can exert huge pressure at ground level. Air pushes in all directions at ground level with a force of over 1 kg per sq cm. The weight of the air present in a large room of your house could weigh about 70kg or as much as a person Use air pressure to make a simple siphon in the following science experiment: STUFF YOU NEED [MATERIALS]  BOOKS  TAP WATER  THIN, PLASTIC TUBE  2x BOWLS  SCISSORS HOW TO PROCEED [PROCEDURE] 1. Place two plastic bowls on a table or flat surface. Fill one of the bowls about ¾ full with tap water and place it on a stack of books so that it is about 200-300mm higher than the other bowl standing on the table. 2. Place the other bowl next to the first bowl on the books. 3. Now, cut a piece of plastic or rubber tubing about 500-600mm long and place the one end inside the bowl with the water on top of the books. 4. Suck on the free end of the tubing until all the air is removed and the tubing is full of water. Place your tongue over the end of the tubing to prevent the water from escaping. 20 5. Remove your tongue from the open end of the tubing and carefully place your finger over the end to hold back the water. 6. Position the end of the tubing in the second bowl and watch what happens WORKING UNDER PRESSURE 2 Propel a small boat with compressed air STUFF YOU NEED [MATERIALS]  STYROFOAM SLAB OR TRAY  DRINKING STRAW  BALLOON  STICKY TAPE HOW TO PROCEED [PROCEDURE] 1. Make the shape of a small sail boat by cutting out a boat shaped platform out of a sheet of high density Styrofoam or Balsa wood. A good size for the boat in this experiment would be about 200mm x 80mm ask an adult to help you when working with a knife or a saw. 2. Make the edges nice and smooth with a suitable fine sandpaper. 3. Next, make a hole for the straw in the centre of the back of the boat to fit through. 4. Fix a balloon on one end of the drinking straw nearest to the bendy part and seal it to be air tight with sticky tape. 21 5. Slide the straw through the hole at the back of the boat with the bendy part just below the surface of the boats bottom, and cut the excess piece of the straw short. If necessary, fix the straw in position with sticky tape the idea is to have a short jet that is pointing towards the back of the boat for propulsion. 6. Blow up the balloon and whilst holding the balloon closed so that the air does not escape, place the boat in a body of water and let the boat set off. Have fun with your very own jet propelled boat ROCKET SCIENCE UNDER PRESSURE Launch your own horizontal rocket with the power of air pressure INTRODUCTION [METHOD] The human fascination with space travel has existed for many centuries and in 1969, Neil Armstrong became the first human being to set foot on the moon It takes a lot of energy to break through the earths gravitational force and the atmosphere to outer space. A rocket is a very powerful machine which obtains thrust or propulsion by ejecting a jet of fast moving fluid exhaust from its engine, and is used to travel from the earth out to space. Let us explore how rockets work with this simple science experiment: STUFF YOU NEED [MATERIALS]  STRING  LONG BALLOON  DRINKING STRAW  STICKY TAPE  SCISSORS  2x CHAIRS 22 HOW TO PROCEED [PROCEDURE] 1. Slide a straight drinking straw over a piece of string of about 3 metres long. 2. Place two chairs about 2 to 2,5 metres apart and tie the string between them to their backs. Move one of the chairs slightly away from the other to make sure the string is stretched tight. The drinking straw should be able to move freely along the taut string. 3. Now, blow up a long party balloon and while holding the end close, ask a friend to tape the balloon to the drinking straw. 4. Move the drinking straw with the balloon to one of the chairs so that the open end of the balloon is next to the chair. Release the end so that the air in the balloon can escape and see how fast your rocket moves along the string PARACHUTE PLEASURE Study how a parachute floats down to earth so slowly INTRODUCTION [METHOD] Gravity constantly pulls all objects towards the earths surface. A parachute is designed to slow down the effect that gravity has on a falling object, by catching air and compressing it under an umbrella shaped object as it falls down. This decreases the rate of fall rapidly, making it safe for humans or other delicate objects to be dropped from the sky and landing softly and safely. In this science experiment we will test how effective this concept can be by making our own parachute: STUFF YOU NEED [MATERIALS]  STRING  DUSTBIN LINER  CARDBOARD BOX 23  STICKY TAPE  EGGS HOW TO PROCEED [PROCEDURE] 1. Use a small cardboard box as the base of the parachute and fix a piece of string to each corner of the top of the box with sticky tape. 2. Cut out a square sheet of plastic of about 500x500mm out of dustbin liner. 3. Using sticky tape, attach the free ends of the four pieces of string fixed to the cardboard box earlier, to each end of the square piece of dustbin liner. Make sure that each piece of string has the same length about 400-500mm so that the cardboard box stays upright when falling down through the air. 4. Now, taking a few eggs with you - go to a safe, high place from where the parachute can be launched, such as a balcony at your home or school. 5. Drop an egg from the balcony without the parachute and notice how quickly it falls down and breaks on the ground. Next, place an egg in the cardboard box of your parachute and drop it from the balcony again. Your parachute will float down to the earth at a much slower rate preventing the egg from breaking when it reaches the ground 24 LEMBAR KERJA SISWA LKS A. Pendahuluan Sains merupakan disiplin ilmu yang mempelajari objek alam dengan metode ilmiah Sund, 1989. Objek tersebut meliputi benda-benda di sekitar anak. Air, udara, bunyi, api, tanah, tumbuhan, hewan, dan dirinya sendiri merupakan objek-objek sains yang sering menjadi perhatian anak. Berbagai gejala alam seperti hujan, angin, petir, kebakaran, hewan yang beranak dan bertelur, tumbuhan yang berbunga dan berbuah yang menarik perhatian anak juga merupakan objek sains. Objek-objek tersebut dipelajari melalui metode ilmiah yang disederhanakan. Menurut NSTA National Science Teacher Association 2005 salah satu standar sains adalah sains sebagai cara penyelidikan science as inquiry. Standar ini menyatakan pentingnya melatih anak melakukan “penyelidikan” terhadap berbagai fenomena alam. Observasi, eksplorasi, dan eksperimentasi melakukan pengukuran, menggunakan bilangan, dan melakukan klasifikasi merupakan kegiatan belajar sains melalui proses inquiry. Untuk memandu siswa melakukan proses inkuiri sains digunakanlah Lembar Kerja Siswa LKS.

B. Pengertian LKS