And now in step two, we basically want to replace all these forces with the right side of these equations. So this becomes we have m omega squared r minus in parentheses. We have misplaced multiplied by omega squared r plus this quantity here. So the coefficient of friction multiplied by V, and the sum is equal to zero. Now, the question is what exactly is the mass displaced? How else can we represent the displaced mass of that fluid that is displaced by that particle?