Zajęcia naukowe napięcie powierzchniowe


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Zajęcia naukowe napięcie powierzchniowe

  1. 1. Kindergarten No 240 Warsaw, PolandDensity, surface tension, properties of liquids
  2. 2. Floating, sinking paper clipMake sure you’re in a place where it’s ok if water spills, prepare some papertowels.You will need:A soup plate, a paperclip, liquid soap or dishwashing soap, tap water
  3. 3. ProcedureFill up the soup plate withwater. Hold your paperclipflat against the edge of thecup and carefully slide it Conclusiontoward the middle of the cup. The surface tension of water isThe paperclip should be strong enough to even supportfloating on top of the water. a paperclip. When you put thePut a drop of liquid soap into soap into the water, it disrupts the order of the waterthe water. Your paperclip will molecules. The surfacesink. tension isn’t strong enough to support the weight of the paperclip, so the paperclip falls into the water just as quickly as if you had dropped it into the soup plate.
  4. 4. Why the boat is made of steel floaton water when a bar of steel sinks? You will need: A soup plate, plasticine (a type of modeling clay) , tap water
  5. 5. Procedure: Conclusion:Fill the soup plate with cold tap The clay ball sinks in the water. The samewater. Separate two walnut-size amount of clay, when formed into the shape of a boat, floats on the surface of the water.pieces of clay. The pieces should Different phisical phenomena, includingbe of equal size. Roll one of the density, buoyancy, and surface tension, explainclay pieces into a ball. Carefully the floating and sinking of objects. The averageplace the clay ball on the surface of density of a boat -- the combination of thethe water in the bowl. Remove the steel and the air -- is very light compared to theclay ball from the water and set it average density of water. So very little of theaside. Take the second piece of boat actually has to submerge into the waterclay and form it into a boat. Gently before it has displaced the weight of the boat. In other words the boat floats because it takesplace the clay boat on the surface up more space than the clay ball of equalof the water. weight; thus, it has a lower density. Buoyancy is this upward water pressure pushing on the bottom of the boat that is causing the boat to float. Objects with a density lesser than water will float. The weight of the water displaced by an object is equal to the buoyant force exerted by the water on the object. The larger-size clay boat displaces more water, making it more buoyant than the smaller clay ball of equal weight.
  6. 6. A festival of colorYou will need:A soup plate, whole milk, food dyes, dishwashing soap, cotton swabs.ProcedurePour milk in the soup plate. Add a few drops of food colorings of your choice.Now submerge a cotton swab in dishwashing soap. Touch the soapy end of thecotton swab in the middle of the dyes in milk and hold it there for 10 to 15seconds.
  7. 7. ConclusionMilk contains fat. Dishwashing soaprepels fat molecules (the same ishappening when we wash the dishes).Fat is "pushed aside". Along with fatmolecules food coloring dyes also move.
  8. 8. How to make oil ran away?You will needA soup plate, water, cotton swabs, dishwashing soap, cooking oil.ProcedurePour water into a plate. Add a few drops of cooking oil. Submerge a cottonswab into dishwashing soap and touch a surface of the water near thecooking oil. At first oil will rush to the outer edges of the plate. After sometime it will stop moving.
  9. 9. ConclusionWhen you add detergent to water the surface tension of the water is lowered.Detergent (also water, oil and everything else) is build from small particlescalled molecules . Detergent is attracted to both water and oil helping them alljoin together. In other words dish soap like water and oil. Imagine a molecule ofdetergent as a piece of string. One end like water, other end like fat. The end ofthe detergent molecule which attaches to fat tries to avoid being around watermolecules (water fearing). By attempting to move away from the watermolecules, the part of molecule which "like" fat ends is pushed up to thesurface. The result is a break in the surface tension of the water. It is very handywhen we wash the dishes with dish soap.