(4) The victim is at least 13 but less than 16 years old and the actor is at least four years older than the victim. Sexual assault is a crime of the second degree. Amended amended 1979, c.178, s.26; 1983, c.249, s.2; 1989, c.228, s.3; 1997, c.194, s.1.
Quick Answer. Pressure is exerted by fluids because of their weight. According to Georgia State University, static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity.
In open column chromatography, gravity is pulling the solvent down while in HPLC we use a pump to push the solvent with up to 20,000psi of pressure through the column.