Thinking: Insert a chopstick into a cup filled with rice and lift it. Chopsticks can lift rice and cups.
Up?
Materials: a plastic cup, a rice cup and a bamboo chopstick.
Operation:
1. Fill the plastic cup with rice.
2. Press the rice in the cup by hand.
3. Hold the rice with your hands and put chopsticks between your fingers.
4. Gently lift chopsticks with your hands, and the cup and rice are lifted together.
Explanation:
Due to the extrusion between rice grains in the cup, the air in the cup is squeezed out, and the pressure outside the cup is greater than the pressure inside the cup.
Pressure makes chopsticks and rice grains closely combined, so chopsticks can lift the cup into the rice.
Bottle race
Thinking: two bottles of equal weight, one full of sand and the other full of water, roll down from a height, who will reach the finish line first?
Point?
Materials: two bottles of the same size and weight, sand, water, a rectangular board and two thick books.
Operation:
1. Make a slope with a rectangular board and two books.
2. Pour water into another bottle and sand into the bottle.
3. Put two bottles on the board and let them roll down at the same starting height at the same time.
The bottle filled with water reaches the finish line earlier than the bottle filled with sand.
Explanation:
The friction between sand and the inner wall of the bottle is much greater than that of water, and there will be friction between sand.
Shit, so it's slower than a water bottle.
Creation: change the substances in the bottle and let them compete!
Paid newspaper
Thinking: Without glue, tape and other things, newspapers can stick to the wall without falling off. You know this is
Why?
Material: 1 pencil; 1 newspaper.
Steps:
1. Spread the newspaper and lay it flat on the wall.
2. After a few quick rubs on the newspaper with one side of the pencil, the newspaper won't fall off like sticking to the wall.
Yes
3. Lift a corner of the newspaper, and then let go, and the lifted corner will be sucked back by the wall.
Take the newspaper off the wall slowly and pay attention to the static sound.
Description:
1. Wipe the pencil to charge the newspaper.
2. The charged newspaper was sucked to the wall.
When the air in the room is dry (especially in winter), if you take the newspaper off the wall, it will
Hear the crackle of static electricity.
Creation: Please have a try. What else can be stuck to the wall by static electricity without glue?
Separation of pepper and salt
Thinking: I accidentally mixed the kitchen spices: pepper and salt, how to divide them.
What about driving?
Ingredients: pepper, salt, plastic spoon, small dish.
Operation:
1. Mix salt and pepper.
2. Stir well with chopsticks.
3. Rub the plastic spoon on the clothes and put it on the salt and pepper.
4. Pepper sticks to the spoon first.
5. Move the plastic spoon down slightly.
6. After salt, stick it on the spoon.
Explanation:
Pepper is electrostatically adsorbed earlier than salt because its weight is lighter than salt.
Create:
Can you separate other mixed materials in this way?
Inflatable balloon
Thinking: When will two balloons attract each other and repel each other?
Material: 2 inflatable balloons, 1 string, 1 cardboard.
Operation:
1 Inflate two balloons separately and tie a knot in your mouth.
Connect two balloons with a thread.
Rub the balloon on your hair (or sweater).
Lift the middle part of the rope and the two balloons will separate immediately.
Put the cardboard between two balloons, and the electricity on the balloons makes them attracted to the cardboard.
Explanation:
The electricity on one balloon repels the electricity on the other balloon.
The electricity on the two balloons attracts them to the cardboard.
Creation: Can other small experiments be used to illustrate that balloons are charged?
Lovely watermark
Thinking: The beautiful patterns on rice paper are not drawn, but how are they made?
Materials: 1 washbasin, 1-2 rice paper, 1 chopsticks, 1 cotton swab, 1 bottle of ink and water (about half a basin).
Operation:
1, pour half a basin of water into the washbasin, gently touch the water surface with chopsticks dipped in ink, and you can see that the ink is in the water.
The surface expands into a circle.
2. Wipe the scalp with a cotton swab for two or three times.
3. Then touch the center of the ink circle and see what happens.
4. Gently cover the calligraphy paper on the water, and then pick it up slowly. What patterns are printed on the paper?
Explanation:
1. When the cotton swab touches, the ink will swell into an irregular circular pattern.
2. A small amount of oil on the scalp rubbed by cotton swabs will affect the mutual pulling force of water molecules.
3. The watermark will present irregular concentric circles.
Create:
Try other methods to change the ink pattern on the water surface.
Switching flow
Thinking: Why does a stream of water become a stream when you touch it with your hand?
Material: a tin can, awl, water.
Operation:
1. Drill five holes in the bottom of the empty tin can with nails (the interval between the holes is only 5 mm).
Right).
2. Fill the water tank with water, and five streams of water flow out from five small holes.
Twist these streams together with your thumb and forefinger.
When the hand is removed, the five streams of water will merge into one.
If you wipe the small hole in the jar with your hand again, the water will become five strands again.
Explanation:
The surface tension of water makes the water flow on and off.
Floating needle
Thinking: Why does the needle float on the water?
Ingredients: a bowl of water, needle, fork, detergent.
Operation:
1, pour a glass of water in the cup.
With a fork, carefully put a needle on the water.
Move the fork slowly, and the needle will float on the water.
Drop a drop of detergent into the water and the needle will sink.
Explanation:
1, it is the surface tension of water that supports the needle so that it will not sink. Surface tension is the cohesion formed by water molecules.
Sexual contact. This cohesive connection is due to the fact that some molecules are attracted together and the molecules squeeze each other.
Form a thin film. This kind of film is called surface tension, which can hold the object that should sink.
2, detergent reduces the surface tension, the needle will not float.
Attention: The needle is dangerous, please ask parents to help you operate it.
Magic toothpick
Thinking: Will the toothpick in the water swim with the sugar cubes in the water or with the soap in the water?
Swimming?
Ingredients: toothpick, a basin of water, soap, sugar cube.
Operation:
1. Carefully put the toothpick on the water.
2. Put the sugar cubes in the basin, away from the toothpicks. The toothpick will move towards the sugar cube.
Change a basin of water, carefully put the toothpick on the water, and now put the soap in the basin near the toothpick.
Location. Toothpicks will stay away from soap.
Explanation:
When you put the sugar cube in the center of the basin, it will absorb some water, so there is little water flowing to the square.
Sugar flows in the direction and toothpicks move with the water. However, when you put soap into the basin, the surface around the basin
Tension is strong, so the toothpick will be pulled out.
Creation: Please try. If sugar and soap were replaced by other substances, which direction would the toothpick swim?
Perforated paper can hold water.
Thinking: Why can perforated paper block water?
Material: a bottle, a pin, a piece of paper, a full cup of colored water.
Operation:
1. Fill the empty bottle with colored water.
Punch many holes in the white paper with a pin.
3. Cover the bottle mouth with perforated paper.
4. Hold the paper with your hand, turn the bottle upside down, and make the bottle mouth face down.
Gently remove your hand, the paper will cover the bottle mouth and the water will not flow out of the hole.
Explanation:
A thin piece of paper can hold up the water in the bottle, because atmospheric pressure acts on the paper, producing upward tension. small
This hole will not leak, because water has surface tension and forms a water film on the surface of paper, so water will not leak.
Let's go This is like an umbrella made of cloth. Although this cloth has many holes, it still won't leak rain.
The secret of handkerchief
Thinking: Lay the handkerchief flat under the faucet and turn on the faucet. Does the water run down through the handkerchief?
?
Material: 1 glasses, 1 handkerchief, 1 rubber band.
Process:
1. Cover the cup with a handkerchief and tie it with a rubber band.
2. Let the water flow on the handkerchief.
3. Turn off the tap after the water flows into the cup for about seven or eight minutes.
4. Turn the cup upside down.
Description:
1. When flushing from the top of the cup, water will flow into the cup through the handkerchief.
2. When the cup is inverted, water will not flow out due to atmospheric pressure.
Extension:
If the cloth covered on the handkerchief is different (such as cotton cloth or towel or linen), what will happen to the water in and out?
So what?
Plastic backing plate that won't fall off.
Thinking: Cover a cup full of water with a pad. Will the backing plate fall off when the cup mouth is facing down?
Materials: two glasses, water and a plastic plate.
Operation:
1. Fill the glass with water.
2. Cover the cup with a pad.
Hold the cup in one hand and the mat in the other.
4. Hold it by hand, turn the cup mouth upside down, and let the cup mouth face down.
Let go of the hand holding the pad gently, and the pad won't fall off.
Explanation:
The cushion is covered on the mouth of the cup containing water, because the air pressure outside the cup is relatively high, and the cushion will not fall off.
Create:
There is not enough water in the cup, or what if there is no plastic plate? Please try it.