Often, lids are made of metals which are great conductors of electromagnetic waves (including heat). When warm water is applied to a "difficult" lid, excitement of the atoms in the metal occurs (very slight) which causes a slight expansion. This expansion helps the lid to be moved from it's grip on the jar or bottle. This is also found in plastics. Although not through expansions. The heat from the warm water literally softens the plastic.
Harriet should ask several senior citizens to evaluate whether her jar lid design is easier to use than a traditional jar lid.
Thermal expansion and contraction, specifically the different coefficients of thermal expansion (CTE) between glass and metal....AND ITS LIKE A (CLOSED SYSTEM)
Examples of an inclined plane.
The air inside the tin will expand when heated causing great pressure on the inside of the can. If the pressure inside the can is greater that the force holding the lid on, then the pressure will force the lid to pop off off the can. have to heat it then and go crazy
The lid will expand and loosen the grip on the jar.
A Mason or canning jar.
no
3 things that are translucent are windows, a glass lid, and a glass jar.
Cover it with a thick lid.
I use a glass jar with a screw on lid. It can be frozen and put into the microwave with the lid off to thaw. So, there are several advantages using the jar.
There are two main components to the answer. Both depend upon the fact that metal and glass expand when heated: 1) The metal in the lid might be a kind of metal which expands faster than glass when heated. So, if you heat the jar and the lid together to above room temperature, the lid will become a little too big for the jar, and will come off more easily. 2) If you direct the heat to the lid only, and avoid heating the glass, the lid will get hotter than the glass, and will expand, while the size of the jar remains the original size. This, too, will cause the lid to be too big for the jar, and cause it to come off more easily.
Heating up the lid of a jar causes it to expand slightly, which can help break the seal between the lid and the jar. This makes it easier to open because the expanding metal in the lid relieves some of the pressure that is holding the lid tightly in place.
Heat should not cause a jar to seal more tightly. There is an excellent reason for this, and it lies in the physics of the coefficient of thermal expansion (CTE) of materials. If you run hot water on the (stuck) lid of a glass jar, the jar will undergo only a little thermal expansion. The metal lid however, will expand more than the glass, and will do it more rapidly, too. Running a jar under a bit of hot water should act to loosen the lid instead of tighten it. The CTE of metals is higher than that of glass, and the lid, because it is metal, will also have a higher rate of thermal conductivity than the glass. Thermal energy will move through it more quickly to change its size. This double whammy should not cause the lid of the jar to tighten. If the lid is still stuck, then insufficient force has been applied to it to get it unstuck. Increased care is indicated as efforts are redoubled to remove the lid.
1. If the jar had been previously open, the inside of the lid or the screw area of the jar may have gotten moist from the material in the jar. Putting the jar back in the refrigerator will cool the material on the lid making it less viscose (thicker) and possibly stickier making it harder to separate the lid from the jar. 2. Putting a jar in the refrigerator will make it colder. Because of the physical properties of metal and glass or plastic, the cold will make the metal lid contract/shrink more than the rest of the jar. Although the degree of shrinkage is very small, it could be enought to tighten the lid around the jar making it harder to remove the lid.
Yes. Glass has been around for about 9000 years and glass bottles were produced 3500 years ago. The Jamestown settlers made glass bottles and jars in the early 1600s. Glass jars for preserving food were sealed with a flat tin lid and wax until 1858 when John Mason invented the Mason Jar with a screw-on lid. By 1864 a glass jar would look very similar to a modern peanut butter jar.
Using hot water to open a metal jar lid helps to expand the metal, making it easier to twist open the jar. The heat from the hot water causes the metal to expand while the glass of the jar remains relatively unaffected, creating a temperature difference that helps to loosen the lid.