Because it is balanced by an elastic force due to the compression in the shelf.
Actually the gravity on a picture on a shelf does pull it downward. If the gravity did not act on the picture, it would float away. The reason the picture doesn't go down through the shelf can be explained by Newton's Third Law. Every action has an equal but opposite reaction. The force of the picture on the shelf due to gravity is the same force of the shelf on the picture. Since both forces are the same, the picture remains stationary on the shelf.
Gravity pulls the picture downward, but tension pulls the picture upward toward the nail. The forces are balanced, so the framed picture does not move.
Not sure what you mean by 'rate of gravity'. All objects with mass are attracted to the Earth's centre by a force proportional to the mass of the object. The constant called the gravitational constant produces a downward acceleration of any free falling object of 9.81 meters/sec2, called G. The force on the object is equal to its mass M times G, ie MG Newtons. Now energy equals (force x distance) so if you raise an object H meters, the energy used to do this is MG x H Joules. This then becomes its Potential Energy, potential because this energy is available to do work if the object is allowed to fall. So the object on the shelf has potential energy, the amount being dependent on how far it is going to fall if the shelf is suddenly removed. Obviously potential energy is relative to the level of the observer or the base line.
Use the formula PE = mgh (potential energy = mass x gravity x height). Gravity is approximately 9.8 m/s2. Answer will be in Joule.
110
Actually the gravity on a picture on a shelf does pull it downward. If the gravity did not act on the picture, it would float away. The reason the picture doesn't go down through the shelf can be explained by Newton's Third Law. Every action has an equal but opposite reaction. The force of the picture on the shelf due to gravity is the same force of the shelf on the picture. Since both forces are the same, the picture remains stationary on the shelf.
Gravity pulls the picture downward, but tension pulls the picture upward toward the nail. The forces are balanced, so the framed picture does not move.
Gravity pulls the picture downward, but tension pulls the picture upward toward the nail. The forces are balanced, so the framed picture does not move.
continental shelf
It means one needs to hang the picture better or to place it safer on the shelf. It means that the law of gravity is immutable. That's all. Setting aside simple physics makes no sense, not even, or especially, when you want to asign some supernatural meaning to it.
The continental shelf
The continental shelf is an extension of the cotton, only beneath water. The continental slope begins beyond the shelf and slopes downward.
The part of a continent that dips gently downward and is underwater is called the continental shelf. When a continent drops steeply in to the ocean it is called a continental slope.
The geologic edge of a continent is typically defined by the continental shelf, which is the submerged part of the continent that slopes downward into the ocean basin. This transition from the continental shelf to the deep ocean is called the continental slope.
I don't have access to images, but the Elf on the Shelf tradition began in 2005, so there wouldn't be pictures of it from 1963. It was created as a children's picture book in 2005 and became a popular holiday tradition in many households.
The potential energy of the book on the shelf is equal to the work done to lift the book to the shelf. This is because the potential energy of an object at a certain height is equivalent to the work done against gravity to lift it to that height.
picture 4 packs of cards in a square. around that size to the shelf.