Tas watches as his uncle changes a flat tire on a car. his uncle raises the car using a machine called a jack. each time his uncle pushes down on the jack handle, the car rises up. tas sketches the jack and labels it using the symbols f, to represent force, and d, to represent distance. he uses large and small letters to compare the sizes of the forces and distances. which set of labels is correct for the side of the jack that tas’s uncle pushes on?

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.