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What is friction and its types?

‘Friction‘ is a force that resists motion of sliding or rolling of one object moving relative to another. It is a result of the electromagnetic attraction between the charged particles of two touching surfaces.   Types of Friction Static Friction : It is defined as the frictional force that acts between the surfaces when they are at rest with respect to each other. The magnitude of the static force is equal in the opposite direction when a small amount of force is applied. When the force increases, at some point maximum static friction is reached. Rolling friction : It is the force that resists motion when an object rolls on a surface. Technically it’s not friction; its ‘rolling resistance’ since when a body rolls perfectly upon a surface, on paper, there is no sliding friction between that object and surface. Sliding friction : It is the frictional force between two surfaces that are rubbing against each other. It’s a very easy and common concept. It’s hard to find a perfectl...
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Heat and types of transmission of Heat

 

Heat energy is called Heat. When an object is very hot, it generally possesses a lot of heat energy; similarly, when the object is cold, it has less heat energy. 

Transmission of Heat

The heat can be transferred from one place to another in different ways-

Conduction

Conduction mostly happens in a solid-state. All liquids (except mercury) and gases are poor conductors of heat. When a solid heat up, its molecules gain kinetic energy and increase the energy with which they vibrate. Conduction occurs when heat energy travels through a body, passing from one particle to another particle as they vibrate against each other. A good conductor must have particles that are close enough together to collide with sufficient force for energy to be transferred from one place to another.

Convection

Convection is the way in which heat flows through liquids and gases. Take a vessel of cold liquid soup on your stove and put it on the stove. The soup in the bottom of the pan, closest to the heat, warms up quickly and becomes less dense than the cold soup above. The soup which is warmer rises upward, and the colder soup above it comes down to take its place. Pretty soon, you've got a circulation of heat running through the pan, a bit like an invisible heat conveyor, with warming, rising soup and cooling, filling soup. Gradually, the whole pan heats up.

Radiation

Radiation is the way we get heat energy from the sun. This radiation does not require a medium for its transmission such that it can travel through empty space, and this radiation is in the form of electromagnetic energy waves, which travel in a similar way as light or radio waves

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What is friction and its types?

‘Friction‘ is a force that resists motion of sliding or rolling of one object moving relative to another. It is a result of the electromagnetic attraction between the charged particles of two touching surfaces.   Types of Friction Static Friction : It is defined as the frictional force that acts between the surfaces when they are at rest with respect to each other. The magnitude of the static force is equal in the opposite direction when a small amount of force is applied. When the force increases, at some point maximum static friction is reached. Rolling friction : It is the force that resists motion when an object rolls on a surface. Technically it’s not friction; its ‘rolling resistance’ since when a body rolls perfectly upon a surface, on paper, there is no sliding friction between that object and surface. Sliding friction : It is the frictional force between two surfaces that are rubbing against each other. It’s a very easy and common concept. It’s hard to find a perfectl...
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What is non-metal?

A non-metal is a material which do not have properties of metals like lustre. They are non malleable, non ductile, non sonorous and bad conductor of heat and electricity. Example- Carbon, Sulphur, Phosphorous. Non-metals are the elements which form negative ions by accepting or gaining electrons. Non-metals usually have 4, 5, 6 or 7 electrons in their outermost shell. Very few elements in the periodic table are non-metals. These are present on the right-hand side in the periodic table. Elements that come under non-metals are sulphur, carbon, all halogens, phosphorus, hydrogen, oxygen, selenium, nitrogen and noble gases. Properties of Non-metals : High ionization energies High electronegativities Poor thermal conductors Poor electrical conductors Brittle solids-not malleable or ductile Little or no metallic luster Gain electrons easily Dull, not metallic-shiny, although they may be colorful Lower melting points and boiling point than the metals  Some special facts : Uses of non-...
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Why is the Earth called Blue Planet?

“The Earth has almost 70% water on its surface due to which it looks blue in color”. or “ More than 71% of the earth is covered with water. Hence, its is known as the blue planet ”. Why Earth looks blue from space? The Earth has extremely hot red heat under its crust and the top outer surface is covered with water. The Earth’s surface has many oceans and seas starting from the Arctic Ocean to the Southern Ocean. These oceans & seas cover almost 70% of Earth’s surface and the remaining 30% is covered with land. It means that almost 70% of Earth’s surface appears blue from outer space & the leftover 30% looks greenish-brownish. This is the reason why Earth looks blue from outer space.  
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