Question

A rigid uniform bar AB of length L 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 vortical is θ. 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 A is a parabola
[C] Instantaneous torque about the point in contact with the floor is proportional to sin θ
[D] When the bar makes an angle θ with the vertical, the displacement of its midpoint from the initial
position is proportional to (1–cos θ)

Answer 1

Explanation:

A rigid uniform bar AB of length L 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 vortical is θ. 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 A is a parabola

[C] Instantaneous torque about the point in contact with the floor is proportional to sin θ

[D] When the bar makes an angle θ with the vertical, the displacement of its midpoint from the initial

position is proportional to (1–cos θ).