Physics

Sonar (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.

A micron is equal to 0.001 mm.

Kinetic energy depends on both mass and velocity of the moving body.

Adding salt raises the boiling point of water, which allows food to cook at higher temperature. The higher the temperature, the higher the rate of heat transfer between the food and water, thus it cooks more quickly.

Kinetic energy is the supplied heat energy stored during change in temperature of substance.

Light scattering takes place in colloidal solution. Colloid refers to substance which is extremely small and is known for equal dispersion through another material. In colloidal solution any matter is evenly suspended in the liquid.

The basic reason for the extraordinary sparkle of suitably cut diamond is that it has a very high refractive index.

Decibel (dB), unit for expressing the ratio between two physical quantities, usually amounts of acoustic or electric power, or for measuring the relative loudness of sounds. One decibel (0.1 bel) equals 10 times the common logarithm of the power ratio.

The inside of a car with its windows closed is hotter than outside due to green house effect as the glass in the windows absorb infrared radiations of the sun but do not allow them to escape or reflect back, thus increasing the temperature of the car on the inside.

Pa(Pascal) is the unit for pressure.