A rectangular copper loop of mass $100$ g and resistance $2\mathrm{.}0$ is in a region of uniform magnetic field of strength $3\mathrm{.}0$T that is perpendicular to the area enclosed by the ring and horizontal to Earth$$s surface $($see below$).$ The width of the loop is $=25$cm$.$ The loop is let go from rest when it is at the edge of the nonzero magnetic field region. $($a$)$ If the loop were long enough for it to reach terminal velocity before exiting the region of magnetic field, what would be its terminal velocity? $($b$)$ Find an expression for the speed as a function of time while the top of the loop is still in the magnetic field.