1. The problem statement, all variables and given/known data You are conducting an experiment inside a train car that may move horizontally along rail tracks. A load is hung from the ceiling on a string. The load is not swinging, and the string is observed to make a constant angle of with the horizontal. No other forces are acting on the load. Which of the following statements are correct? Statements include: The train is an inertial frame of reference. The train is not an inertial frame of reference. The train may be at rest. The train may be moving at a constant speed in a straight line. The train may be moving at a constant speed in a circle. The train must be speeding up. The train must be slowing down. The train must be accelerating. Please help, and if you could, explain why as well. I am doing these as practice for an exam and would really like to lock down the concept.