He removes two strips of tape from the roll. He presses each strip of tape, sticky-side down, on a plastic surface.
He quickly removes each strip of tape from the plastic surface.
Ike's teacher tells him that this process has caused each strip of tape to gain a negative electric charge. What could Ike do next to demonstrate that the negative charge of each strip has generated an electric field?

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.