Okay. So, for part (c), I thought of integrating the change in radius function with respect to time, which can then be rearranged to a function that tells you time for a specific radius (treated it as integration of a constant). Can anyone tell me if this logic is flawed?
Homework Statement
Imagine a planetesimal sweeping up small particles from a dust cloud. Suppose the planetesimal, of mass M and radius R, is moving through the cloud at a velocity v. There are nd dust particles per m3, each of mass md
(a) Derive an expression for the number of collisions per...