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25. A rod of length L is held vertically on a smooth horizontal surface. The top end of the rod is given a gentle push. At a certain instant of time, when the rod makes an angle ∂ with horizontal the velocity of COM of the rod is v. The velocity of the end of the rod in contact with the table at that instant is:
(a) zero
(b) v cos∂
(c) v sin ∂
(d) v tan∂
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5 Answers
21velocity of the upper end is 2v in y direction and v tan∂ in x direction//////
let q be the displacement of upper end in y direction//
we must have (p + y - q)2+ h2 = p2
differentiate it , and put (p+ y -q) =h tan∂
thus we get dq/dt = 2v ( velocity in y direction)