1. The problem statement, all variables and given/known data A 3kg object hangs at one end of a rope that is attached to a the ceiling of a railroad car. When the car accelerates to the right, the rope makes an angle of 4 degrees with the vertical. Find the acceleration of the car. 2. Relevant equations (sigma)F=ma ..and I think that's it. 3. The attempt at a solution First, as always, I drew a free-body diagram of what is described in the problem. When the object is 4 degrees with the vertical, the weight force vector of it is pointed straight down, the tension vector pointed to the top right along the string that attaches it to the ceiling of the car. What about the (x) vectors? Are there two equal magnitude vectors pointing in opposite directions? I'm confused at wether or not the object is still or if it is still moving. I suppose that it is still though. This is a review problem by the way, and I have lost my acumen for Newtons laws, force diagrams, etc. Please guide me through the steps of solving this problem. By all means, feel free to admonish me on anything that I may be doing wrong. Thanks!