Things become static when they release or receive electrons from other materials and thereby become electrically charged. For example, hair gets a positive charge when you pull a wool sweater over your head, because it releases its electrons. Positive charges repel each other, causing your hair to stand apart to escape from each other.
Category: Physical phenomena
The rule of thumb is that hot water is lighter than cold water, but that is not always true. Fresh water is the heaviest at 4 ° C. So in a vessel with water of 2, 3 and 4 ° C respectively, the hottest water will sink to the bottom. The temperature of the water is a measure of the movement of the molecules.
The air resistance is the biggest opponent of the Tour de France rider. But if the air contains a lot of water vapor, that resistance is smaller. That is why a cyclist can ride faster in damp air than a cyclist in dry air who pedals just as fast. Due to the water vapor, the mass of the air decreases, so that the same amount of air weighs less.
Black surfaces, such as car upholstery or a black sweater, warm up faster than white surfaces on a sunny day. That is because white and black surfaces have very different physical properties. The energy-rich particles of light fall on the electrons of the atoms in the black clothing and make them vibrate.
This is what you need A bottle of 2 tbsp of dry yeast 3 tbsp of warm water 1 dl of hydrogen peroxide 1 dl of detergent Food coloring This is how you work Dissolve the yeast in the warm water and let it stand for a while. Pour the hydrogen peroxide into the bottle. Also pour the detergent into the bottle. Add food coloring - blue and red, for example, so that it looks like real toothpaste.
The doppler effect describes how the pitch of a sound changes as the sound source and the receiver move relative to each other. A well-known example is the siren of an ambulance, which sounds lower when the vehicle has passed us. ### Siren makes sound Brain creates sound Sound is an experience that your brain creates based on pressure differences in the air.
The sound waves of an aircraft go in all directions, but because the aircraft moves, the sound waves are compressed in front of the aircraft. The faster the aircraft goes, the less space there is between the top and bottom of these sound waves. Around the speed of the sound, around 1220 km / h, the waves are compressed so strongly that they form a wall in the shape of a shock wave.
The 'wagon-wheel effect' is an illusion: wheels, propellers and rotor blades seem to stand still or turn backwards in the film. This is because film and TV cameras record 24 or 25 images per second. If the wheel rotates 25 times per second, the camera will always see the wheel in the same position for each frame.
This is what you need Oil - for example, sunflower or olive oil Water Food colorant An effervescent tablet - it doesn't matter what kind, as long as the water starts to fizz A transparent bottle This is how you work Fill the bottle for a third with water. Pour in oil until the bottle is three-quarters full. Wait until water and oil have separated into two layers.
Researchers from the University of Tokyo have created the most powerful magnetic field ever observed in a controlled experiment. The field was so strong that the research equipment exploded. The 1200 tesla far exceeded the expectations of the researchers - they thought they could only generate 700 tesla.
Salt lowers the freezing point of water because it makes it difficult for water molecules to form ice crystals together. Salt is a chemical compound of sodium and chlorine. When salt comes into contact with water or ice, the salt crystals are dissolved and positive sodium ions and negative chloride ions are released.
In fact, all atoms are small magnets, but in the vast majority of materials the atomic magnets are arranged randomly, so that their magnetic fields cancel each other out. However, ferromagnetism occurs in a number of metals. A ferromagnetic metal such as iron has magnetic domains: areas in which the atomic magnets face the same direction.
The American MIT has designed one of the strongest materials that exist. Using heat and pressure, they compressed layers of graphene - a two-dimensional wonder material that is only one carbon atom thick. For example, the researchers made a new 3D material that has a porous, spongy structure and is ten times stronger than steel.
Vandet, du fylder i din kedel, pumped on fra undergrunds. På sin vej fra overfilling til grundvandslagrene tager of the mineraler med sig og ender derfor med at the hollowskilled ioner: atomer eller molekyler med and elektrisk ladning. Still less positive or negative ion than when tungtopløselige ionforbindelser, the bliver synlige sum bundfald eller belægninger.
Pressure is all around us: it can cause your ears to slam shut while flying or diving, it determines whether the weather will be nice or rainy, but it can also be deadly - for example, the pressure wave of an explosion. Pressure is the force that an object exerts on a certain surface. Or more physically speaking: the ratio between the force exerted on a surface at a perpendicular angle and the size of this surface.
You need this. A porcelain bowl (not plastic). 30 grams of powdered sugar A long lighter This is how you proceed Fill the porcelain bowl with dry sand. Mix baking powder / soda and powdered sugar well.
This is what you need A glass 2 dl vinegar 1 egg This is how you work Put the egg in the empty glass. Pour the vinegar over it. Let it stand for two days. Carefully remove the egg and start playing with it. What is happening? An eggshell consists almost entirely of lime, which dissolves when exposed to a mild acid such as vinegar.
This is what you need 2 tablespoons double-carbonated soda 1 dl washing-up liquid 5 dl hot water Food coloring 2 dl table vinegar 1 (plastic) bottle 1 soil soil How to do Put the double-carbonated soda in a transparent bottle of at least one liter. Add the washing-up liquid and the warm water. Pour in a few drops of dye.
Do you add milk, sugar, cream or sweets to your coffee? Then there is a lot in it that you don't spoil yourself with the ultimate comfort. According to experts and researchers from Oxford University, among others, five steps are needed for the perfect coffee. 1. The right roasting of coffee Coffee beans must be heated considerably to bring out their aroma and taste.
If you doubt whether the water in a mug is hot or cold, you can of course find out by using your sense of touch. But did you also know that you can determine the temperature by only listening to liquid while it is being poured? Try it yourself Your brain has unknowingly learned to hear the difference between the sound of hot and cold water based on all the times you have poured drinks.
This is what you need A bowl of Potato flour Water Food coloring This is how you work Put about 2 deciliters of potato flour in a bowl. Add water and food coloring and stir until the net is liquid. Experiment with the consistency. Add some more water or potato flour if necessary. Play with your non-Newtonian fluid.