An object is at x = 0 at t = 0 and moves along the x axis according to the velocity–time graph in figure p2.50.(a) what is the object’s acceleration between 0 and 4.0 s? (b) what is the object’s acceleration between 4.0 s and 9.0 s? (c) what is the object’s acceleration between 13.0 s and 18.0 s? (d) at what time(s) is the object moving with the lowest speed? (e) at what time is the object farthest from x = 0? (f) what is the final position x of the object at t = 18.0 s? (g) through what total distance has the object moved between t = 0 and t = 18.0 s?

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.