The device shown is used to produce the experience of weightlessness in a passenger when...

The device shown is used to produce the experience of weightlessness in a passenger when he reaches point A, θ = 90°, along the path. If the passenger has a mass of 75 kg, determine the minimum speed he should have when he reaches A so that he does not exert a normal reaction on the seat. The chair is pin-connected to the frame BC so that he is always seated in an upright position. During the motion his speed remains constant.