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Will the mass of earth reduce due to extraction of fossil fuels?

Is it possible that the earth mass would be reducing due to extraction of fossil fuels? 
If so, would it affect to its movement and position in solar system?


fossilfuelandearthThere won’t be any considerable loss of mass. The amount of mass irrecoverably lost is negligibly small on its conversion to energy .

It’s just like arguing that constructing more and more buildings will increase the mass of earth. !! No such thing happens. There is only a rearrangement of matter and inter conversion of mass and energy.

gravitation problem

if the orbital velocity of moon is 1020 m/s ,find the time taken by moon to complete one revolution around earth explain why this period is different from the period that is observed from earth which is 29.5 days (dist of moon from earth is 3.4*10*8m

Asked Ravinder

Principle of Working of Microwave Oven

Manisha Chowdhury asked:

Why is it called a microwave oven?
Who invented it?
What is the principle of its working?


A microwave oven is used to cook (or heat) food with the help of microwaves produced by magnetron – the device producing microwaves in the oven. Microwave ovens are so quick and efficient because they channel heat energy directly to the molecules (tiny particles) inside food.

Who invented Microwave Oven?

Percy-spencerPercy Spencer is generally credited with inventing the modern microwave oven after World War II from radar technology developed during the war. Named the “Radarange”, it was first sold in 1946. Raytheon later licensed its patents for a home-use microwave oven that was first introduced by Tappan in 1955, but these units were still too large and expensive for general home use. The countertop microwave oven was first introduced in 1967 by the Amana Corporation, and their use has spread into commercial and residential kitchens around the world.

Working of microwave oven

microwave ovenA microwave oven, commonly referred to as a microwave, is a kitchen appliance that heats and cooks food by exposing it to electromagnetic radiation in the microwave spectrum. This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer25–38 mm (1–1.5 inches) of a homogenous (high water content) food item; food is more evenly heated throughout (except in heterogeneous, dense objects) than generally occurs in other cooking techniques.

Magnetron2A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of non-ionizing electromagnetic radiation with a frequency higher than ordinary radio waves but lower than infrared light. Microwave ovens use frequencies in one of the ISM (industrial, scientific, medical) bands, which are reserved for this use, so they don’t interfere with other vital radio services. Consumer ovens usually use 2.45 gigahertz (GHz)—a wavelength of 12.2 centimetres (4.80 in)—while large industrial/commercial ovens often use 915 megahertz (MHz)—32.8 centimetres (12.9 in). Water, fat, and other substances in the food absorb energy from the microwaves in a process called dielectric heating. Many molecules (such as those of water) are electric dipoles, meaning that they have a partial positive charge at one end and a partial negative charge at the other, and therefore rotate as they try to align themselves with the alternating electric field of the microwaves. Rotating molecules hit other molecules and put them into motion, thus dispersing energy. This energy, when dispersed as molecular vibration in solids and liquids (i.e. as both potential energy and kinetic energy of atoms), is heat.

For more details refer to :


Nature of Electromagnetic Waves

When we represent the frequency, amplitude, and wavelength of any electromagnetic radiation on a graph we see a wave like in water. Is this just a geometric representation or do the “packet” aspects of these waves actually move physically like the mathematical representation.

Asked Jack Cassidy

Hope that the following videos explain the concept better

English: Electromagnetic waves can be imagined...
English: Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. This diagram shows a plane linearly polarized wave propagating from left to right. The electric field is in a vertical plane and the magnetic field in a horizontal plane. http://weelookang.blogspot.com/2011/10/ejs-open-source-propagation-of.html (Photo credit: Wikipedia)

Air and Liquid Pressure

Does air pressure in a capped bottle is different as that of open bottle??

If not and the atmospheric pressure in a closed container is same as that of the surroundings let 1bar at sea level, if i consider a
tube both end open and dip one end in water (like pipette in chemistry lab) and close the other by thumb, water remain
hanged in the tube..  if we say it is because the atmosphere that pushes up on the water in the tube is same as that of remaining air in tube pushing down on the water..won’t the water fall out due to its own weight as the upward and downward pressure is balanced…

Please explain the whole process and compare weight of water with up and down pressure by atmosphere..

Again would liquid ‘ll flow out of a container through a hole in vacuum??


 Asked Shashank Patra

The Air Pressure in an open bottle is equal to the atmospheric pressure. The pressure inside a closed bottle can be different.

In the experiment described, when the tube is partially filled and the upper end is closed, the water tries to fall down creating a lower pressure above it inside the tube. This creates a pressure difference, the outside pressure greater than the pressure inside and the water can fall only upto the level where the weight of water column is balanced by the force due to difference in pressure created.
See one live demonstrations here


  • A guide into hydraulics – Part 1

Solar Power

Suppose a PVC solar cell converts or absorbs 30% of the electromagnetic radiation which falls upon it, where I understand that “Gamma rays” or the such simply pass through it, would it not be so that a large portion of the 70% not converted, if directed to yet another PVC, could this second PVC convert 30% of the reflected 70% which the first PVC did not convert?


monokristalline Solarzelle

I believe the answer is “Yes, for the most part” which would than imply that the unabsorbed portion of the second pass could be directed again to a third PVC.

Is this correct?


Asked Edward


Electric potential due to a dipole

If a point lies at a distance x from the midpoint of the dipole the electric potential is?


Asked Sai Mohan




If the distance x is along the equatorial plane (a plane passing through the midpoint and perpendicular to the axis), the potential will be zero.


Please clarify what did you mean.


English: Potential field due to an electric dipole
English: Potential field due to an electric dipole (Photo credit: Wikipedia)



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