Express one parsec second in terms of light years.

Define a light year.

Define one second.

If Planck's cosntant (h) and speed of light in vaccum (c ) are taken as two fundamental quantities, which one of the following can, in addition, be taken to express length, mass and time in terms of the three chosen fundamental quantities?

Express partial pressure in terms of mole fraction.

Define a second in terms of vibrations of caisium -133 atom.

The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun ?

If velocity of light c, Plank's constant h and gravitational ontant G are taken as fundamental quantities then express mass, length and time in terms of dimensions of these quantities.