Last question for the semester, but Physics II is right around the corner!! This is an easy question but I am not sure how to answer it! A steel ruler is accurate when the temperature is 25 degrees celsius. When the temperature drops to -15 degrees celsisus the ruler no longer reads correctly, but it can be made to read correctly if a stress is applied to each end of the ruler . Should the stress be compression or a tension? Why? I think the answer is tension, but I really have no idea why! Thanks!