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What happened when the water finally flowed off the penny explain in terms of the chemical and physical forces involved?
As drops of water are added onto a penny, the adhesive force between the water and the penny keeps the water from falling off. The “skin” will burst, and all of the water will spill off. The cohesive forces between polar molecules are stronger than those between non-polar molecules, such as those in oil or syrup.
What happens to water when you place the candle fire at the bottom of the tin can?
The water level stays up for many few minutes more. Because twice as much oxygen is burned than carbon dioxide released, the air volume decreases. The physical aspect: the candle heats the air and expands it. This cancels the depletion of the oxygen temporarily and the water level stays down.
What happened to the can and needle when placed in water did they sink or float in water?
The needle is more dense than the water, and would be expected to sink. However, the surface of the water can support the needle because of the force of surface tension. When the needle is sideways on the surface it can’t break through the surface; the water can support the needle and keep it “floating”.
What happens when you tap the water on its surface?
Due to the surface tension, small objects will “float” on the surface of a fluid, as long as the object cannot break through and separate the top layer of water molecules. When an object is on the surface of the fluid, the surface under tension will behave like an elastic membrane.
Do you see the coin before the water is poured into the glass what about after explain your answer?
When the cup is filled with water, the penny disappears. This happens because of refraction. When light bounces off of an object, it reaches our eyes and we see the object. As light travels through the sides of the glass and the water, it’s refracted and never reaches our eyes, which makes the penny seems to disappear.
What have you observe in the burning candle when it is covered?
Explanation: When a burning candle is covered with an inverted jar, the candle flame extinguishes soon after. This happens because in order for the candle to burn, it requires the presence of oxygen. This supply of oxygen gets limited when the jar is placed on the flame, thus extinguishing the flame, eventually.
What happens when you drop a needle in water?
A metal needle or paper clip has higher density that that of water. So when it is dropped into water, it falls down into the bottom of water. However, if we put it horizontally on the water with a lot of caution, it can float almost forever due to the surface tension of water.
What do you think contributes to the adhesion of the insect paperclip and blade on water?
The high surface tension helps the paper clip – with much higher density – float on the water. The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.
How do you measure surface tension in water?
To observe surface tension on a liquid surface, bend the sharp end of a pin into a hook or make a hook with a piece of thin wire. Polish the hook to make it sharp. Fill a glass cup with water. Immerse the end of the hook then gently lift it up. The hook does not pierce the water surface but lifts it slightly.
Why does paper toweling stay attached to glass?
Place a plate with four pieces of paper toweling on top of the glass and then turn the assemblage over. After about one minute you can lift the glass and the plate will remain attached to the toweling and glass because a partial vacuum has been established in the glass when the toweling absorbed water.
What is the density of a buoy at low tide?
A spherical buoy of radius 25 cm and mass 8 kg sits in sea water of density 1025 kg/m3 . At low tide its anchoring chains have got tangled. What is the maximum tension force this chain may have to… The average human has a density of 940 kg/m^3 after inhaling and 1028 kg/m^3 after exhaling.