A rigid uniform bar AB of length ? is slipping from its vertical position on a frictionless floor (as shown in the figure). At some instant of time, the angle made by the bar with the vertical is `theta.` Which of the following statements about its motion is/are correct?
A. The midpoint of the bar will fall vertically downward
B. The trajectory of the point ? is a parabola
C. Instantaneous torque about the point in contact with the floor is proportional to `sintheta`
D. When the bar makes an angle `theta` with the vertical, the displacement of its midpoint from the initial position is proportional to `(1−costheta)`
