Please help. I do not understand

The soot produced by a garbage incinerator spreads out in a circular pattern. The depth, HQ"), in millimeters, of the soot deposited each month at a distance 1" kilometers from the incinerator is given by H(r) = 0.1115 1'5\". {a} Write a denite integral {with independent variable 1"] giving the total volume of Soot deposited within 5 kilometers of the incinerator each month. volume = I: E] {include units] {b} Evaluate the integral you found in part {a} to find the volume of Soot. volume=l:] {include units]