3.) In class, we solved for the velocity v(t) of a mass falling under gravity with quadratic drag. Even simpler is the case of linear drag: m v˙ =−mg−bv Here m is the mass, g is the gravitational acceleration, and b>0 is the strength of the air drag. Note that in this coordinate system, up is positive. This ODE is both separable AND linear! (a) What are the SI units of the constant b ? (b) Solve for the specific solution of this ODE using the initial condition v(0)= 0 (the mass starts from rest). You can solve this by treating the ODE as separable, and separating then integrating. Or you can treat it as an inhomogeneous linear ODE, and use the methods we introduced for those. Your choice. (c) Based on your solution to (b), what happens to the velocity as t→[infinity] ? Explain qualitatively.