1. The problem statement, all variables and given/known data http://s12.postimage.org/q2c8bqw97/image.png http://i.imgur.com/6STfr.png The part a is easy and i get the ans, the required speed should be v/cos30 but i really have no clue about how to do the part b i know that the knot will move down and left but i just can't list any equation for the motion 2. Relevant equations the length of string is constant 3. The attempt at a solution i use √X^2 + Y^2 = constant is part a and get the v/cos 30 but i really have no idea about b part any clue please >??