Learn Amazing Fact about Gravity...

Gravitation

Gravitation is the force of attraction between objects in the universe. It exists between objects due to their mass. An object's mass is the amount of matter it contains.

Gravitation enables planets to orbit around the Sun. It is responsible for the existence of the atmosphere around the Earth. It also holds together the hot gases that make up the Sun. The formation of tides in the Earth's oceans is also due to the gravitation. Gravitation is also called gravitational force or simply gravity.

Newton's Law of Universal Gravitatton

Sir Isaac Newton proposed the Law of Universal Grav’lflaltuin 1n his book sz'losop/yz'ae Naturalis Princz’pz’a Matbematzca. e aw states that every object in the universe exerts a force of attractlon on other objects. This force of attraction is called gravitatlonal force. It increases with the increase in the mass of the objects and decreases with the increase inthe distance between the objects. Newton did not discover gravity but he was the first to define gravity mathematically.

Gravity on Earth

Gravity on Earth is the force that tends to pull objects towards the centre of the Earth. It is denoted by ‘g’ and its value is approximately 9.8 m/sz. It is because of gravity that all ohjects on Earth have weight.

Weight

Weight is a fundamental property of all matter. It is dehned as the force of gravity on an object. It is equal'to the mass of the object (m) multiplied by the magnitude of the gravitational held,(g): Weight = mg Weight is the downward force, which acts on a body because of Earth’s gravitational force. It is measured in Newtons (N): 1N=1kgm/s2

Gases

Gases are the least dense state of matter. In a gas, the molecules can move around freely, allowing gas to spread. Gases are thinner and lighter than solids and liquids. They have no shape of their own. They take on the shape of their container. A gas has no fixed shape or fixed volume.

Changing states

Increasing temperature or increasing pressure and freezing something or decreasing pressure often changes the state of matter. As the temperature rises, matter moves to a more active state. When the temperature of a solid rises, it melts and changes into the liquid state. When the temperature of a liquid rises, it boils and changes into the gaseous state. When the temperature of a liquid is lowered, it freezes and changes into its ‘ solid state.

Changing states of water

Water is the only compound that can move from one state to another without undergoing any change in its chemical properties. The molecules of water are very loosely packed. So water can take any shape. Water usually exists in its liquid state. Liquid water freezes at 0 °C and changes to its solid state. Ice, snow, and frost are examples of water in the solid state. Water evaporates when heated and turns into a gas. Gases are colourless and odourless.
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Glass

Glass 13 solid, but has the molecular structure of a liquid. It is made by melting silica, potash, or lead oxrdc at high temperatures.

Crystals

Crystals. are solids that have organized structures. The molecules in a gas or liquid bounce or flow around each other freely. When a liquid changes into a solid state, the molecules lock together. The molecules link to one another in a uniform pattern that is repeated over and over. This results in the formation of a crystal. Crystals often appear as strange and beautiful geometric shapes. Qiartz, diamond, and ruby are the common examples of crystals. Quartz always grows in the shape of six-sided columns.