The magical power of chopsticks
Thinking: Insert a chopstick into a cup filled with rice, and then lift the chopstick up. The chopstick will lift the rice and cup
Get up?
Materials: One plastic cup, one cup of rice, one bamboo chopstick
Operation:
1. Fill the plastic cup with rice.
2. Press the rice in the cup with your hands.
3. Hold the rice with your hand and insert the chopsticks between your fingers.
4. Gently lift the chopsticks with your hands, and the cup and rice will be lifted together.
Explanation:
Due to the squeeze between the rice grains in the cup, the air in the cup is squeezed out, and the pressure outside the cup is greater than inside the cup
The pressure makes the chopsticks and rice grains tightly bonded together, so the chopsticks can lift the rice cup.
Bottle Race
Thinking: Two bottles of equal weight containing sand and water roll down from a height, who reaches the end point first
?
Materials: two bottles of the same size and weight, sand, water, a rectangular board, two thick books
Operation:
1. Use The rectangular wooden board and the two books form a slope
2. Pour the water into another bottle and pour the sand into the bottle
3. Place the two bottles on the wooden board , let the two bottles roll down at the same starting height at the same time
4. The bottle filled with water reaches the end point earlier than the bottle filled with sand
Explanation:
The friction between sand and the inner wall of the bottle is much greater than the friction between water and the inner wall of the bottle, and there is also friction between the sand
, so its sliding speed is slower than that of the bottle filled with water.
Creation: Change the substances in the bottles and let them compete!
Electric newspapers
Thinking: Without glue, tape or other adhesives, newspapers can be stuck on the wall without falling off. Do you know why?
Materials: 1 pencil; 1 newspaper.
Steps:
1. Unfold the newspaper and lay it flat on the wall.
2. After quickly rubbing the side of the pencil on the newspaper a few times, the newspaper will not fall off as if it is stuck to the wall.
3. Lift up a corner of the newspaper and then let go. The lifted corner will be sucked back by the wall.
4. Slowly peel the newspaper off the wall and listen for the sound of static electricity.
Instructions:
1. Rub the pencil to charge the newspaper.
2. The charged newspaper was sucked to the wall.
3. When the air in the house is dry (especially in the winter), if you peel the newspaper off the wall, you will
hear the crackle of static electricity.
Creation: Please give it a try, what other items can be stuck on the wall using static electricity without using adhesives
Separation of pepper and salt
Thinking: I accidentally mixed the kitchen seasonings: pepper and salt together. How to separate them
?
Materials: pepper, salt, plastic spoon, small plate
Operation:
1. Mix salt and pepper together.
2. Stir evenly with chopsticks.
3. Rub the plastic spoon on the clothes and place it on top of the salt and pepper.
4. The pepper sticks to the spoon first.
5. Move the plastic spoon downward slightly.
6. The salt sticks to the spoon.
Explanation:
The reason why pepper is electrostatically adsorbed earlier than salt is because its weight is lighter than salt.
Create:
Can you use this method to separate other mixed ingredients?
Electric Balloons
Thinking: Under what circumstances will two balloons attract each other, and under what circumstances will they repel each other?
Materials: Inflated Balloons 2 , 1 piece of string, 1 piece of cardboard
Operation:
1 Inflate the two balloons separately and tie a knot at the mouth.
2 Connect the two balloons with string.
3 Rub the balloon on your hair (or sweater).
4 Lift the middle part of the string and the two balloons immediately separate.
5 Place cardboard between two balloons and the electricity on the balloons causes them to be attracted to the cardboard.
Explanation:
1 The electricity on one balloon repels the electricity on the other balloon.
2 The electricity on the two balloons causes them to be attracted to the cardboard.
Creation: Can you use other small experiments to show that the balloon is charged?
Cute watermark
Thinking: How are the beautiful patterns on rice paper made if they are not drawn?
Materials: 1 washbasin, 1-2 pieces of rice paper, 1 chopstick, 1 cotton swab, 1 bottle of ink, water (about half a basin)
Operation:
p>
1. Pour half a basin of water into the basin and gently touch the water with chopsticks dipped in ink. You will see the ink expand into a circle on the surface of the water
.
2. Take a cotton swab and rub it on the scalp two or three times.
3. Then tap the center of the ink circular pattern and see what happens.
4. Gently cover the calligraphy paper on the water, and then slowly pick it up. What pattern is printed on the paper?
Explanation:
1. When the cotton swab is touched, the ink will expand into an irregular circle shape.
2. The small amount of oil applied when the cotton swab is rubbed on the scalp will affect the force of water molecules pulling each other.
3. The watermark will appear in irregular concentric circles.
Create:
Try other ways to change the shape of the ink on the water.
Breaking and converging water flow
Thinking: Why do multiple streams of water turn into one stream of water when you touch it with your hand?
Materials: One tin can box, awl, water
Operation:
1. Use a nail to drill 5 holes in the bottom of the empty tin can box. small holes (the distance between the small holes is only 5 mm left
right).
2. Fill the jar with water. The water will be divided into 5 streams and flow out from the 5 small holes.
3. Use your thumb and index finger to twist the water flows together.
4. After taking your hand away, 5 strands of water will merge into one strand.
5. If you wipe the small hole on the can again with your hand, the water will turn into 5 strands again.
Explanation:
The surface tension of water causes the water flow to divide and merge.
Floating needle
Thinking: Why do needles float on the water?
Materials: a bowl of water, needle, fork, liquid detergent
Operation:
1. Pour a cup of water into the cup
2. Use a fork and carefully place a needle on the surface of the water
2. Slowly remove the fork and the needle will float on the water
3. Drop a drop of detergent into the water and the needle will sink
Explanation:
1. It is the surface tension of the water that supports the needle and prevents it from sinking. Surface tension is the cohesive connection formed by water molecules. This cohesive connection is due to the molecules in a certain part being attracted together and squeezing each other to form a thin film. This thin film is called surface tension, and it holds up objects that would otherwise sink.
2. The detergent reduces the surface tension and the needle cannot float.
Note: Needles are dangerous, parents are asked to help operate them.
Magic Toothpick
Thinking: Will the toothpick placed in the water swim with the sugar cubes placed in the water, or with the soap placed in the water? p>
Swimming?
Materials: toothpicks, a basin of water, soap, sugar cubes
Operation:
1. Place the toothpick carefully on the water.
2. Put the sugar cube into the water basin far away from the toothpick. The toothpick will move towards the sugar cube.
3. Change a basin of water, carefully place the toothpick on the water, and now put the soap in the basin closer to the toothpick.
The toothpick will stay away from the soap.
Explanation:
When you put the sugar cube into the center of the basin, the sugar cube will absorb some water, so a small amount of water will flow to the side
< p>The direction of the sugar flows, and the toothpick also moves with the water flow. However, when you put the soap into the basin, the surface tension on the edge of the basin is relatively strong, so the toothpick will be pulled outward.Creation: Please try to see which direction the toothpick will swim if you replace sugar and soap with other substances
Piece of paper with holes to hold water
< p>Thinking: Why can paper with holes hold water?Materials: a bottle, a pin, a piece of paper, a full cup of colored water
Operation:
p>1. Fill the empty bottle with colored water.
2. Poke many holes in the white paper with a pin.
3. Cover the mouth of the bottle with the perforated paper.
4. Press the paper with your hand and turn the bottle upside down so that the bottle mouth faces down.
5. Gently remove your hand. The paper covers the mouth of the bottle without moving, and the water does not flow out of the hole.
Explanation:
The thin paper can hold up the water in the bottle because the atmospheric pressure acts on the paper, creating an upward force. Small
holes will not leak water because water has surface tension, and water forms a thin film on the surface of the paper, preventing water from
leaking out. This is like an umbrella made of cloth. Although the cloth has many small holes, it still does not leak.
The secret of the handkerchief
Thinking: Spread the handkerchief flat under the faucet, turn on the faucet, will the water flow down through the handkerchief
?
Materials: 1 glass, 1 handkerchief, 1 rubber band
Process:
1. Cover the mouth of the cup with a handkerchief and use a rubber band Tie tight.
2. Let the water wash on the handkerchief.
3. Turn off the faucet after the water flows into the cup until it is about seven to eight minutes full.
4. With the mouth of the cup facing down, quickly turn the cup over.
Instructions:
1. When flushing water from the cup, the water will flow into the cup through the handkerchief.
2. When the cup is turned upside down, the water will not flow out due to atmospheric pressure.
Extension:
If the cloth covering the mouth of the cup is different (such as cotton, towel, linen), what will happen to the inflow and outflow of water?
?
Plastic backing plate that cannot fall off
Thinking: If a cup filled with water is covered with a backing plate, will the backing plate fall off when the mouth of the cup is facing down?
Materials: two glasses, water, one plastic plate
Operation:
1. Fill the glass with water.
2. Cover the mouth of the cup with a backing plate.
3. Hold the cup with one hand and hold the pad with the other hand.
4. Hold it with your hands and turn the cup over so that the cup is facing down.
5. Gently release the hand holding the pad so that the pad will not fall down.
Explanation:
The backing plate covers the mouth of the cup containing water. Because the air pressure outside the cup is relatively large, the backing plate will not fall off.
Create:
What will happen if the water in the cup is not full or there is no water in the plastic plate? Please give it a try?
The candle cannot be blown out
p>Thinking: Blow the burning candle hard, but you can't blow it out.
Do you know how to do this?
Materials: 1 candle, match, 1 small funnel, 1 flat plate
Operation:
1. Light the candle and fix it on the flat plate superior.
2. Make the wide mouth of the funnel face the flame of the candle, and blow forcefully from the small mouth of the funnel toward the flame.
3. Make the small mouth of the funnel face the flame of the candle, and blow forcefully into the flame from the wide mouth of the funnel.
Explanation:
1. When blowing in this way, the flame will tilt toward the wide end of the funnel and will not be easily blown out. If you blow air from the wide
end of the funnel, the candle will be easily extinguished.
2. When the blown gas changes from a narrow mouth to a wide mouth, it gradually evacuates and the air pressure weakens. At this time, the gas around the wide mouth of the funnel will flow into the wide mouth of the funnel due to the strong pressure. Therefore, the flame of the candle will also rush towards the wide mouth of the funnel.
Note: Pay attention to safety when burning candles.
Candle pump
Thinking: Do you know how a water pump pumps out water?
Materials: glass, candle, cardboard slightly larger than the mouth of the glass, plastic tube, a little Vaseline, matches,
half a cup of water
Operation:
1. First fold the plastic tube into a door frame shape, and pass one end through the cardboard
2. Then place the two glasses on the table, one on the left and the other on the right.
p>
3. Light the candle and fix it at the bottom of the left glass, and at the same time pour water into the right glass
4. Apply some Vaseline on the mouth of the cup where the candle is placed, and then wear a plastic Cover the tube with cardboard and submerge the other end of the plastic tube into the water in the cup on the right.
5. Water flows from the right into the left cup
Explanation: The burning candle uses up the oxygen in the left cup, the air pressure in the bottle decreases, and the pressure in the right cup causes the water to flow to the left cup
Flow until the pressure on the water in the two cups is equal. At that time, the water surface of the left cup is higher than the water surface of the right cup.
Note: Pay attention to safety when lighting the candle and fixing it at the bottom of the glass on the left, be careful of burning your hands
Blow up the balloon inside the bottle
Thinking: Blowing up the balloon inside the bottle Balloon, why doesn't the balloon become smaller when you release the mouth of the balloon?
Materials: Large-mouth glass bottle, two straws: red and green, one balloon, air pump
Operation:
1. Use a screwdriver on the bottle cap in advance Punch two holes and insert two straws into the holes: red and green
2. Tie a balloon on the red straw
3. Put the bottle cap on the bottle On the mouth
4. Use an air pump to hit the red straw to make the balloon bigger
5. Release the red straw and the balloon will immediately become smaller
6. Use an air pump to make the balloon bigger.
Use the red straw to make the balloon bigger
7. Quickly pinch the red straw and the green straw tightly
8. Release the red straw and the balloon will not become smaller
p>
Explanation: When the red straw is released, the balloon begins to shrink because the rubber membrane of the balloon shrinks. However, after the balloon
has shrunk in volume, the volume of the air in other parts of the bottle has expanded, and the green tube is closed. As a result, the air pressure in the bottle
will be reduced - even lower than The pressure inside the balloon means that the balloon will no longer shrink.
Cup that can catch balloons
Thinking: Would you use a small cup to gently place it upside down on the surface of the balloon, and then suck up the balloon?
Materials: 1 to 2 balloons, 1 to 2 plastic cups, 1 thermos bottle, a little hot water
Process:
1. Blow up the balloons Inflate and tie up
2. Pour hot water (about 70℃) into the cup for about half a cup
3. After the hot water stays in the cup for 20 seconds, pour the water Come out
4. Immediately place the rim of the cup upside down tightly on the balloon
5. Gently lift the cup together with the balloon
Instructions:
1. If the cup is placed upside down directly on the balloon, the balloon cannot be sucked up.
2. The cup treated with hot water can suck up the
balloon because the air in the cup gradually cools down and the pressure becomes smaller.
Extension:
Children, please think of any other ways to suck up balloons?
A cup that absorbs water
Thinking: Use a glass cup to cover a burning candle. What happens inside the cup after the candle goes out?
Materials: 1 glass (taller than the candle), 1 candle, 1 flat plate, 1 lighter, some water
Operation:
1. Light the candle and put a few drops of wax in the center of the plate to secure the candle.
2. Pour about 1 cm of water into the plate.
3. Use a glass to hold the candle upside down
4. Observe the burning condition of the candle and the changes in the water level in the plate
Explanation:
< p>1. After the air (oxygen) in the glass is consumed, the candle goes out.2. After the candle goes out, the water level in the cup will gradually rise.
Create:
Can you use an empty container to automatically collect other solutions?
A bottle that eats eggs
Thinking: Why can eggs go in from the mouth of a bottle smaller than myself?
Materials: 1 cooked egg, 1 narrow-mouth bottle, some pieces of paper, 1 box of matches
Operation:
1. Peel off the cooked eggs shell.
2. Tear the paper into long strips.
3. Light the note and put it into the bottle.
4. As soon as the fire goes out, snap the egg onto the mouth of the bottle and remove your hand immediately.
Explanation:
1. When the paper is just burned, the bottle is hot.
2. After the egg is fastened to the mouth of the bottle, the temperature inside the bottle gradually decreases, the pressure inside the bottle becomes smaller, and the pressure outside the bottle
increases, which will squeeze the egg to the inside the bottle.
Creation: What happens to the bottle when the pressure of the gas in the bottle is greater than the pressure outside the bottle?
The bottle is deflated
Thinking: Can you deflate a plastic bottle without using your hands?
Materials: 2 water cups, 1 cup of warm water, 1 mineral water bottle
Operation:
1. Pour warm water into the bottle and touch it with your hands Touch the bottle to see if it feels hot.
2. Pour the warm water out of the bottle and quickly close the cap tightly.
3. Observe that the bottle slowly deflates.
Explanation:
1. Heat the air in the bottle to reduce its pressure.
2. Because the air outside the bottle has a greater pressure than the air inside the bottle, the bottle is crushed.
Create:
If the pressure of the gas in the bottle is greater than the pressure of the air outside the bottle, what will the bottle look like?
A table tennis ball that can jump long distance
Thinking: If a table tennis ball is placed in a goblet, how do you blow to make the ball jump out of the cup?
Materials: 2 goblets, 1 table tennis ball
Operation:
1 Place two goblets side by side
2 Place the ping pong ball in the first cup.
3 Blow air from different angles to see how the table tennis ball is doing: blow air toward the side of the ball; blow air toward the top of the ball
Blow air
Explanation:
1. Blow to the side of the ball. The table tennis ball will not easily jump into the second cup (or jump out).
2. Blow to the top of the ball. When you blow the air, the pressure above becomes smaller, and the ping pong ball will float. If you continue to blow, it will jump into the second cup
Creation: Use a new method to make the ping pong ball jump. Go to the next cup
The bottle that blows bubbles
Thinking: Do you know how the bottle blows bubbles?
Materials: 1 beverage bottle, 1 cup of hot and cold water, 1 cup of colored water, 1 large plate, 1 piece of plasticine, and some straws
Dry
< p>Operation:1 Connect the straws one by one to form a long tube (the connections are sealed with tape).
2 Put the straw into the bottle, seal the mouth of the bottle with plasticine, and then place the bottle on the plate.
3 Bend the straw so that the other end of the straw goes into the glass of colored water.
4 Pour hot water on the wall of the bottle, and the straw in the cup will release a lot of bubbles.
5 Pour cold water on the walls of the bottle.
6 The water in the glass will flow into the bottle through the straw.
Explanation:
1 Because the plastic bottle is very thin, heat can pass through the bottle wall and enter the air in the bottle.
2 The air in the bottle expands when heated.
3 The bubbles in the water are the air that is squeezed out of the bottle when the air expands.
4 The air in the bottle shrinks when it gets cold.
5 As the air in the bottle contracts, water takes up the remaining space.
Creation: When the bottle cap is too tight, do you know the best way to open it?
A cup that can walk on its own
Thinking: The cup has no legs, how does it walk down from above?
Materials: a cup, candles, matches, glass , two books, water
Operation:
1. Use a glass plate and soak it in water
2. Place one end of the glass on the table , the other end is padded with a few books (height is about 5 cm)
3. Take a glass, dip the rim of the glass into some water, and place it upside down on the glass plate.
4. Use a lit candle to burn the bottom of the cup, and the glass will slowly move downward on its own.
Explanation:
When the candle burns at the bottom of the cup, the air in the cup gradually heats up and expands, trying to squeeze out. However, the mouth of the cup is upside down
Yes, there is another layer of water that seals the mouth of the cup, and the hot air
cannot escape. It can only lift the cup up a little, and then it will slide down under its own weight.
Paper cup rotating light
Thinking: Why does the candle paper cup light rotate?
Materials: 2 paper cups, 1 toothpick, 1 candle, 1 roll of tape, 1 rope, 1 pair of scissors
Operation:
1. Take a paper cup, cut a large square mouth at each symmetrical part of the cup body, and fix a candle on the bottom of the cup as the base of the lamp
.
2. For another paper cup, cut out three or four rectangular fan blades at approximately equidistant positions on the cup body, put a string on the center of the bottom of the cup
and secure it with toothpicks. , as the upper seat of the lamp.
3. Tape the two paper cups up and down to fix them with tape.
4. Light the candle, pull up the rope, and see what happens.
Explanation:
1. When a candle burns, the tip of the flame mostly points upward.
2. The air will rise when heated, and then flow along the fan blades of the paper cup above, causing rotation.
Create:
Can you make the candle paper cup light rotate in the opposite direction?
Attention:
Pay attention to safety when burning candles!
Flying plastic bags
Thinking: Why do plastic bags fly in the sky when there is no wind?
Materials: plastic bag (lightweight), 1 hair dryer
Operation:
1. Open the plastic bag and turn it upside down. Insert the hair dryer into the plastic bag and turn on the heat switch.
2. After a few seconds, turn off the hair dryer and remove it.
3. Let go and the plastic bag will float.
Explanation:
1. The hot air is light and rises, causing the plastic bag to rise as well.
2. Heat energy makes objects fly because hot air rises. When air is heated and rises, the hot air moves upward through "convection". The heat radiated from the heater warms the entire room, also with the help of "convection".
Create:
Can you try making a simple hot air balloon?
Quality of air
Thinking: Did you know that air also has quality? How to prove that air also has quality?
Materials: 1 scale, 2 balloons of the same weight, pump
Operation:
1. Place the two balloons on both sides of the scale. end, the scale remains balanced.
2. Pick up another balloon, inflate it and tie the mouth of the balloon tightly.
3. Place the inflated balloon on one end of the scale, and the uninflated balloon on the other end of the scale, and observe the changes in the scale
Explanation:
1. Before the two balloons are inflated, their masses are equal, so the scale remains balanced.
2. The inflated balloon increases the mass of the air inside the balloon. Therefore, the balance is biased towards the inflated end of the balloon.
3. If it is a balance with a pointer scale, the mass of air can be measured.
Creation: Can you use other methods to weigh the mass of air?
The formation of clouds
Thinking: Do you know how clouds in the sky are formed?
Materials: 1 cup of cold water, 1 pair of scissors or awl, 1 box of matches, 1 straw, 1 piece of plasticine, glass bottle (with
rotatable lid)
Operation:
1 Poke a hole in the bottle cap, insert a straw into the hole, and seal around the straw with plasticine.
2 Pour some cold water into the bottle, shake it evenly, and then pour the water out.
3 Close the mouth of the bottle and light a match.
4 Blow out the match, throw the smoking match into the bottle, and let the smoke enter the bottle.
5 Quickly tighten the bottle cap and blow forcefully into the bottle through the straw.
6 Stop blowing and block the straw with your hand to keep the air in the bottle.
7 Release the straw and when the air rushes out of the bottle, a cloud is created in the bottle.
Explanation:
1. Blow air into the bottle to increase the pressure.
2. After loosening the straw, the air pressure drops and the air becomes colder.
3. The water vapor in the bottle attaches to the dust particles in the smoke and condenses into very small water droplets. Many small water droplets
form clouds.
Create: Can you create clouds in other ways?
Note: Be careful not to burn your hands with matches
Light and Rainbow
Think: How can you make a rainbow with the same color as the rainbow in the sky?
Light and Rainbow
p>
Materials: 1 basin of clean water, 1 flat mirror
Operation:
Insert the mirror into the basin at an angle, with the mirror facing the sunlight, on the wall opposite the basin You can see a beautiful rainbow from above.
Explanation:
When you insert the mirror into the water, you can see a beautiful rainbow on the opposite wall. It is the refraction of light.
Create:
Children, think about it, is there any other way to create a beautiful rainbow?
The appearance and disappearance of buttons
Thinking: Children, when the chopsticks are inserted halfway into the water, what you see is that the chopsticks are "broken". What is the reason for this?
Materials: 1 button, a little water, 1 shallow bottom plate, 1 glass
Process:
1. Place the buttons on the plate.
2. Put the mouth of the cup up and press it on the button.
3. Pour water into the cup.
4. The button cannot be seen clearly in the cup after filling it with water.
5. Add some water to the plate so that the buttons can be seen.
Instructions:
1. When the cup is gradually filled with water, the image of the button will disappear due to the refraction of light.
2. Add water to the plate and change the refraction angle of the light, and the button image will reappear.
Extension:
When light enters water from air, or enters glass from air, some refraction will occur. So,
please think about it Think about it, what other examples of light refraction are there in life
Understanding buoyancy
Thinking: When we lie on the water and float like a sailboat, we all know that it is the buoyancy of the water. Supporting us.
But do you know how to measure buoyancy?
Materials: 1 spring scale, 1 lock, 1 glass filled with water
Operation:
1. First hang the lock under the spring scale, Record the scale of the spring scale.
2. Then put the lock hanging on the spring scale into the water and record the scale of the spring scale at this time.
3. Compare the scales recorded twice and think about why they are different.
Explanation:
1. When the lock is immersed in water, it will receive the upward support force of the water on it, that is, buoyancy.
2. The difference between the two records is the buoyancy of the water on the small copper lock.
Create:
Use a spring balance to weigh other objects (such as small wooden blocks, rubber heads, etc.) and observe whether the buoyancy of different objects is greater or smaller
.
What happens when an ice cube melts?
Think: Place an ice cube in a cup and fill it with water. When the ice melts, will the water in the cup overflow?
?
Materials: 1 ice cube, 2 cups, water
Operation:
1. Place an empty cup on the tray and put Add a piece of ice.
2. Fill the cup with water so that a large part of the ice cube is above the water.
3. Wait for the ice cubes to melt. Observe whether the water will overflow the cup after melting.
Explanation:
When water freezes, its volume increases by nine percent, so its mass becomes lighter and it will naturally float on the water. When an ice cube melts
it loses the nine percent it gained, so the water doesn't spill out.
In fact, the part of the ice cube below the water surface is the volume of water in the entire ice cube.
The mystery of automatic rotation
Thinking: Why does the carton filled with water rotate?
Materials: Empty milk cartons, nails, 60 cm long rope, sink, water
Operations:
1. Use nails in the empty milk cartons Punch five holes
2. One hole is in the middle of the top of the carton, and the other four holes are in the lower left corner of the four sides of the carton
3. Plug a piece of about 60 Tie a centimeter-long rope to the hole at the top
4. Place the carton on the plate, open the mouth of the carton, and quickly fill the carton with water
5. Use Lift the rope on the top of the carton, and the carton rotates clockwise
Explanation: The water flow produces an equal and opposite force, and the four corners of the carton are all subjected to this thrust.
Since
this force acts on the lower left corner of each side, the carton rotates clockwise
Create:
1. If on each side If a hole is punched in the center, how will the carton rotate?
2. If the hole is located at the lower right corner of each side, in which direction will the carton rotate?
Boat and Ship Pulse
p>Thinking: Have you ever seen rowing? Rowing your own boat? Do you know why a boat moves forward on water?
Materials: 1 pair of scissors, 1 piece of cardboard, 1 rubber band, 1 wash basin and 1 basin of water
Process:
1. Cut a length of approx. 12cm x 8cm cardboard
2. Cut one end into a pointed shape to be the bow, and cut a gap of about 5cm in the center of the other end to be the stern
3. Cut a piece of about Use a 3cm x 5cm cardboard to paddle the boat
4. Put a rubber band on the stern of the boat and tie the boat paddle
5. Turn the cardboard paddle counterclockwise to tighten the rubber If you turn the cardboard paddle clockwise and tighten the rubber band, the boat will move backwards
Explanation:
1. Rubber band The direction of twisting is different, and the direction of the ship's travel is also exactly opposite.
2. The power of the paper boat movement comes from the energy of the twisting of the rubber band.
Extension:
Carefully observe the action of rowing. What is the relationship between the direction of the water flow caused by it and the direction of the boat?
Water pressure
Thinking: Do you know what determines the size of water pressure?
Materials: 1 rectangular vertical carton for milk, 1 roll of tape, 1 nail, some water, flat plate
Operation:
1 . Place the milk carton and poke three holes on either side with a nail. The positions of the three holes are bottom,
center and top.
2. Seal the three holes with tape.
3. Fill the paper box with water.
4. Place the flat plate under the side with holes and peel off the tape.
The magical power of chopsticks
Thinking: Insert a chopstick into a cup filled with rice, and then lift the chopstick up. The chopstick will lift the rice and cup
Get up?
Materials: One plastic cup, one cup of rice, one bamboo chopstick
Operation:
1. Fill the plastic cup with rice.
2. Press the rice in the cup with your hands.
3. Hold the rice with your hand and insert the chopsticks between your fingers.
4. Gently lift the chopsticks with your hands, and the cup and rice will be lifted together.
Explanation:
Due to the squeeze between the rice grains in the cup, the air in the cup is squeezed out, and the pressure outside the cup is greater than inside the cup
The pressure makes the chopsticks and rice grains tightly bonded together, so the chopsticks can lift the rice cup.
Bottle race
Thinking: Two bottles of equal weight containing sand and water roll down from a height, who reaches the end point first
?
Materials: two bottles of the same size and weight, sand, water, a rectangular board, two thick books
Operation:
1. Use The rectangular wooden board and the two books form a slope
2. Pour the water into another bottle and pour the sand into the bottle
3. Place the two bottles on the wooden board , let the two bottles roll down at the same starting height at the same time
4. The bottle filled with water reaches the end point earlier than the bottle filled with sand
Explanation:
The friction of sand against the inner wall of the bottle is much greater than the friction of water against the inner wall of the bottle, and there is also friction between the sand
, so its sliding speed is slower than that of the bottle filled with water.
Creation: Change the substances in the bottles and let them compete!
Electric newspapers
Thinking: Without glue, tape or other adhesives, newspapers can be stuck on the wall without falling off. Do you know why?
Materials: 1 pencil; 1 newspaper.
Steps:
1. Unfold the newspaper and lay it flat on the wall.
2. After quickly rubbing the side of the pencil on the newspaper a few times, the newspaper will not fall off as if it is stuck to the wall.
3. Lift up a corner of the newspaper and then let go. The lifted corner will be sucked back by the wall.
4. Slowly peel the newspaper off the wall and listen for the sound of static electricity.
Instructions:
1. Rub the pencil to charge the newspaper.
2. The charged newspaper was sucked to the wall.
3. When the air in the house is dry (especially in the winter), if you peel the newspaper off the wall, you will
hear the crackle of static electricity.
Creation: Please give it a try, what other items can be stuck on the wall using static electricity without using adhesives
Separation of pepper and salt
Thinking: I accidentally mixed the kitchen seasonings: pepper and salt together. How to separate them
?
Materials: pepper, salt, plastic spoon, small plate
Operation:
1. Mix salt and pepper together.
2. Stir evenly with chopsticks.
3. Rub the plastic spoon on the clothes and place it on top of the salt and pepper.
4. The pepper sticks to the spoon first.
5. Move the plastic spoon downward slightly.
6. The salt sticks to the spoon