what is physics


2. Show that the function $\phi$: R→R defined by $\phi$(x) = $e^{-x}$ + 2 is the solution of the differential equation y' + y = 2, y(0) = 3.
Solution: $\phi$(x) = e -x + 2 => $\phi$'(x) = -e -x If we replace y by $\phi$(x), we have y'+ y = $\phi$'(x) + $\phi$(x) = -e -x + e -x + 2 = 2 $\phi$ (x) satisfies the equation y' + y = 2 Moreover, $\phi..
Physics and technology
. Based on the principles of physics, people design and build skyscrapers, bridges and roads. From all these examples it is clear that physics has a great role in the development of technology and in our daily lives. To conclude, Physics is a very vast subject and has ..
Physical equilibrium
The equilibrium established between two physical forms of a chemical substance, is called physical equilibrium, viz. change of water into vapour at normal temperature in a closed vessel. Water and vapour are same as chemical substance but their physical forms are liq..
NUCLEAR PHYSICS
The discovery of radio - activity marked the beginning of the development of nuclear physics. Rutherford's discovery of nucleus and the artificial radio-activity have shown that nucleus has got its own structure. The structure and properties of the nucleus was further established b..
Physical Equilibrium
Equilibrium is also attained in physical processes such as vaporization and condensation. The conversion of a liquid into vapour is known as vaporization, while the opposite process, i.e., the conversion of a vapour into liquid is called condensation. The molecules of a liquid that..
PHYSICAL PROPERTIES
1. Physical state: Dimethyl ether and ethyl methyl ether are gases at room temperatures. Other lower members are colourless liquids, which are highly volatile. 2. Boiling points: Ethers have much lower boiling points compared to isomeric alcohols as they are not associated with..
Physical properties
(1) Taste : Acids have a sour taste. Mineral acids like H 2 S0 4 and HN0 3 are highly corrosive in nature. Therefore, they should not be tasted. (2) Physical state : Some acids are solids and some are liquids at room temperature. For example : ..
MODERN PHYSICS
X-rays were discovered by Rontgen in 1895. Becquerel, in 1896, performed some experiments. He observed that salts of uranium affect a photographic plate covered with black paper after several hours of exposure. Becquerel further discovered that such radiations are the property of uranium salt. As..
PHYSICAL OPTICS
Phenomena of light such as reflection, refraction, formation of images by mirrors and lenses are successfully explained by the assumption that light travels in straight lines. In all these phenomena light interacts with objects whose size is much larger than the wavelength of light (of the o..