272 A block is pulled along a horizontal rough surface by a tension T in a cord inclined at an angle 0 to the horizontal. The coefficient of sliding friction is u, and the block is moving with constant velocity. The block weighs w. WT (a) Prove that the tension T is equal to LW Horiz cos O + usin 0 (b) Prove that the minimum T is given by the expression LOW Hint: d1 273 A flexible chain of weight w rests on a smooth cone in a horizontal plane. The cone has height h and radius r. Prove that the tension in the chain is - wh chain 2 zr (Requires integration.)