Questions

Maglev trains are used in Japan, South Korea and China only.

Maglev derived from magnetic levitation using the principle of magnetic repulsion is a system of train transportation that uses two sets of magnets, one set to repel and push the train up off the track as in levitation then another set to move the 'floating train' ahead at great speed taking advantage of no friction. Maglev trains are therefore quieter and smoother than conventional trains, and have the potential for much higher speeds

Despite over a century of research and development, maglev transport systems are in operation in just three countries Japan, South Korea and China.

Hence Maglev -- Magnetic-levitation.

Capital refers to buildings and equipment i.e, goods which are used by workers to produce other goods such as machinery, land, ...

Capital has a number of related meanings in economics, finance, and accounting.

In economics, Capital comprises one of the four major factors of production, the others being land, labor, and entrepreneurship.

In finance and accounting, capital generally refers to financial wealth, especially that used to start or maintain a business.

Ideal Gas Law ::

The Combined gas law or General Gas Equation is obtained by combining Boyle's Law, Charles' Law, and Gay-Lussac's Law. It shows the relationship between the pressure, volume, and temperature for a fixed mass (quantity) of gas:

P1V1T1 = P2V2T2

Hence, the Boyle's law P1V1 = P2T2, relates to ideal gas equation.