1. The problem statement, all variables and given/known data http://img21.imageshack.us/img21/6784/probi.jpg [Broken] 2. Relevant equations 3. The attempt at a solution i have no idea where to begin and my textbook doesnt have any examples that look like this question.. can someone give me hints? whats the equation that l=10m after some time t, if it reduces by 0.031m/h ?