Let R be the region bounded by the following curves. Use the shell method to find the volume of the solid generated when R is revolved about the x- axis. y = Sqrt x , y = 0, and x = 81
V = ? (Type an exact answer in terms of pi)

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days