Physics Exercises/Forces

Suppose you are in a moving train. Assume it is moving with a constant acceleration. You have just come from the mall, and have with you only a ball of string, a long ruler, and a massive paperweight. Describe how to find the acceleration of the train using these items. Assuming that the train accelerates at 3 m/s2, what would you measure? 200px|thumb|The booster and 2nd stage engines of the Soyuz rocket. Why are the booster engines of the Soyuz rocket inclined at a small angle to the 2nd (central) stage? What are the advantages and disadvantages of this design?