John and Barry are pulling on a fence post with ropes while their friend Pat uses a chain-saw to shear it at ground level. John applies a force of 75.0 N [40 degrees] on one rope while Barry applies a fore of 85.0 N [340 degrees] on the other rope. What is the net force on the post?

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.