Consider an arbitrary radionuclide X (τ = 30 min), which decays to the stable nuclide Y through β− decay. If a sample contains 2 pmol1 of X, what is the activity of this sample? If the sample were allowed to stand for a period of 7 hours, what would be its activity?

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

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.

The amount of potential energy possessed by an elevated object is equal to