The explanation of buoyancy, how to explain buoyancy to children and how to let children explain buoyancy.

How to explain buoyancy to children and how to make them explain the goal of buoyancy activities;

1, knowing that salt can increase the buoyancy of water and make some sinking things float. 2, interested in scientific activities, can actively explore and find answers. Activity preparation: 1. Children's experience: I know that some things will float on the water and some things will sink under the water. 2. Activity process of eggs, cups, sugar, salt, monosodium glutamate, water and rags: 1. Teacher and children reviewed the ups and downs together: Teacher: Children, everyone did ups and downs experiments with their parents at home on Sunday, so who can tell us about your experimental results? Second, the magical "egg floating": 1, Question: Did any children put their eggs in the water e68a84E8a2ade799be5baa6e97ae7ad94313336163? So are the eggs submerged or floating in the water? 2. Let the children do experiments-the eggs sink into the water. 3. The teacher pretended to do magic, showing a glass of water with salt, adding eggs, and the eggs surfaced. 4. Question: Why do children's eggs sink to the bottom and teachers' eggs float on the water? 5. Teacher: I added a mysterious thing to the water. Do you know what this is? The teacher took out salt, sugar and monosodium glutamate and asked, I just added one of these three good friends to the water. Guess who it is? I won't tell you today, let you find out for yourself! Third, the children tried the experiment. The teacher divided the children into 9 groups, each with four eggs, four cups, a stirring stick and four glasses of water. The experiment was carried out, and three kinds of spices were put on each table. Experimental results: eggs can float in salt water. 1. Children add things to the water according to their own ideas. After the experiment, they told, "What did you add to the water? What happened to your eggs? " The experiment concluded that adding salt to water can make eggs float, but adding sugar and monosodium glutamate can't. 2. After changing the water, put salt in the water together, stir it, then add the eggs, observe the results and experience the happiness of success. After the experiment, it is concluded that putting salt can increase the buoyancy of water and make eggs float. Fourth, extension activities: Teacher: "Salted water can make eggs float. Can that man float? " Interpretation of physical buoyancy formula F float =G object -F pull F float = ρ liquid gV discharged F float =F up -F down.

F float =G row [edit this paragraph] The concept of buoyancy. Liquid and gas have a vertical upward supporting force for the object immersed in it. This supporting force is called buoyancy in physics. The buoyancy direction is vertical upward. Objects floating on the surface of fluid or immersed in fluid are subjected to the upward resultant force of hydrostatic pressure from all directions. Its size is equal to the gravity of the fluid displaced by the object. In liquid, the pressure at different depths is different. The immersion depth of the upper and lower parts of an object in liquid is different, and the upward pressure of the liquid on the lower part of the object is greater, which can prove that buoyancy is equal to the difference between the upward and downward pressure of the liquid on the object. For example, E68A84E79FA5E981933133332623939 If the gravity of a stone is greater than that of the same volume of water, it will sink to the bottom of the water. The gravity of driftwood or hull is equal to the weight of the water displaced by the submerged part, so it floats on the water. The weight of the balloon is less than the gravity of the same volume of air, that is, the buoyancy is greater than gravity, so it will rise. This kind of force immersed in water or air and pulled up by water or air is called "buoyancy". For example, lifting a bucket of water from a well is lighter before leaving the water surface than after leaving the water surface, because the bucket is buoyed by the water. Not only water, but also all liquids, such as alcohol, kerosene or mercury, have buoyancy for objects immersed in it. All liquids are the same. The action point of buoyancy is called the center of buoyancy, which obviously coincides with the center of mass of the displaced liquid volume. [Edit this paragraph] The cause of buoyancy can be analyzed by immersing a regular cube in a liquid. The completely submerged object in this system is under the pressure of liquid from all directions, and it increases with the increase of depth. So the front, back, left, right, upper and lower surfaces of this regular cube are all under the pressure of liquid. Because the forces acting on the left and right sides correspond to each other, have the same area and the same depth in the liquid, the pressures on both sides are equal in magnitude and opposite in direction, and the two forces are balanced with each other. Similarly, the pressures acting on the front and rear sides are balanced with each other. However, due to the different depths of the upper surface and the lower surface in the liquid, the pressure is not equal. The pressure above is small, and the pressure below is large. The upward pressure below is greater than the downward pressure above. The pressure difference between a liquid and an object is the buoyancy of the liquid to the object. This force is equal to the weight of the liquid displaced by the object. When the top interface of the floating body does not touch the liquid, only the upward pressure acting on the bottom interface will produce buoyancy. As for the object located at the bottom of the container and in close contact with the bottom of the container, it can only be subjected to the liquid pressure acting downward on the surface of the object, so the object is not affected by buoyancy. This phenomenon is rare, because as long as there is a thin liquid film in the middle, the pressure can be transmitted, and there will be upward pressure on the bottom. If there is a pressure difference between the upper and lower surfaces of an object, the object will be floated. Calculation of buoyancy formula in Newton n [edit this paragraph] The calculation of buoyancy formula assumes that a cube sinks into the water, f floats =F lower surface -F upper surface = ρ GH2 * s-ρ GH1* s = ρ GS * Δ H = ρ GV = mg = g When the object is suspended on the liquid (without external force), f floats slightly = g. (2) "F flotation = ρ gV drainage =G drainage" is the most important. F-Float = ρ gV row formula derivation: buoyancy = gravity of displacement liquid -F-Float =G-Drain = M-Drain Explain what is the law of buoyancy? The buoyancy of an object invading a liquid is equal to the gravity of the liquid it displaces. See Archimedes principle for details.

How to explain the buoyancy problem? 12-5=7 N, the gravity of the liquid is equal to the buoyancy, which is also 7 N, unchanged.

Find the explanation of physical buoyancy in ninth grade. Like I said, you can think and understand. * Used for multiplication.

1, you need to know about "water pressure", which is very important. We know that the relationship between water pressure and depth and water density is P=ρgh, ρ is liquid density, h is depth, and g is gravity coefficient 2. Take a cube as an example. Its side length is L, and it is completely submerged in water. At this time, the distance between the upper surface and the water surface is a, and the upper surface is subjected to water pressure, F 1=ρg*a*L*L, where L*L is the upper surface area. The lower surface is far away from the water surface B, the water pressure is upward, F2=ρg*b*L*L, and the difference between the upper and lower surfaces is F=F2-F 1=ρg*(b-a)*L*L, 3, and the forces on the four sides of the cube cancel each other (obviously, I understand it) 4, b-a. Now it is well understood. For a cube, buoyancy is the difference of water pressure between the upper and lower sides. Get to know it slowly, draw a picture and have a look, don't worry. Here comes the topic: //doc88/p-28 1364608666. I'm happy to answer your question. I wish you progress in your study! Hua Meng Magic Combat Team will answer your questions. You can ask questions if you don't understand! If you agree with E799BE5BAA6E997AEE7ad94E78988E69D8331333261365438, my answer. Please click the button below to choose the satisfactory answer, thank you! As for the physical buoyancy of junior high school, simply explain that because people are floating in the water, zhidao, gravity is equal to buoyancy 80 *10 = 800 N;

Buoyancy F=ρgV, then V = f/ρ G = 0.08m 3, because the volume of people exposed to water is110, that is, the volume in water is 9/10; Therefore, the human volume V' = 0.08/(9/ 10) = 0.9m 3, the third grade physics problem, buoyancy, the knowledge points to be explained: liquid will produce a vertical buoyancy on zd for objects immersed in it.

On land, the pressure of the pen on the president is equal to the gravity of the pen. Under water, the pressure of the pen on the president is equal to the resultant force of vertical downward gravity minus vertical upward buoyancy. Assuming that the pen weighs 1N, on land, the president feels the pressure to answer is1n. Assuming that the pen is buoyed by 0.3N underwater, the pressure felt by the president is only 0.7N N. So the president should think that the pen is lighter in water than on land. How to explain the ups and downs of soap bubbles with buoyancy knowledge is wrong. Reason: At the beginning, due to the high temperature, large volume and high buoyancy in the air, soap bubbles will rise. After a period of time, the gas cooled, the volume contracted, and the buoyancy became smaller, so the bubbles began to fall again.

Buoyancy (4) Baby (1)