A square loop, length l on each side, is shot with velocity v0 into a uniform magnetic field of strength B. The field is perpendicular to the plane of the loop. The loop has mass m and resistance R, and it enters the field at t = 0 s. Assume that the loop is moving to the right along the x-axis, that two of its sides are parallel to the x-axis, and that the field only exists in the positive x region of space. Find an expression for the loop's velocity as a function of time as it enters the magnetic field. You can ignore gravity, and you can assume that the back edge of the loop has not entered the field