1. The problem statement, all variables and given/known data A mass of 1 kg hangs inside a boxcar of a train. If the train accelerates at 7 m/s^2, what is the approximate tension in the rope? A: 12 N 2. Relevant equations F=ma 3. The attempt at a solution I originally thought of doing this problem as pythagorean theorem, but I wanted to work out the x and y components for practice. Breaking up the components: ΣFy=may Ty-mg = may Ty=10N ΣFx=max Tx=10*7 Tx=70N Thus, T2=102+702 T=71 N The problem sets it up just like I do but get 12 N for their answer: T2=ma2+mg2 What am I doing wrong? Thanks in advance!