here is the task: A ship whose mass is 2.0 X 10(to the seventh) kg rests on launching ways that slope down to the water at an angle of 6 degrees. The ways are greased to reduce the coefficient of kinetic friction to 0.11 . Will the ship slid e down the ways into the water by itself? If not, find the force needed to winch the ship into the water. Ive been dealing with this question for 2 days. The first thing that I want to ask is, how can I know that will it slide down by itself or not. I've calcluated its acc. but I got a negative number. My teacher said it is not going to work in that way, so I have to find another way to answer this question. I also dont understand the second part of the question, how could it possible to lift an object and make it to slide down? Im not a native speaker, but Ive checked the meaning of "winch" like 4-5times and it means to lift something. I just can't see the point. Could anybody help me?