Why are space crafts usually launched from west to east? Why is it more advantageous to launch rockets in the equatorial plane

Show that the projection angle thetha_0 for a projectile launched from the origin is given by theta_0 =tan^1(4h_m//R) Where the symbols have their usual meaning.

Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

What are the conditions under which a rocket fired from the earth, launches an artificial satellite of earth?

Explain why steam at 100°C usually produces more severe burn than water at the same temperature.