I've already determined the first part of the question, which is regarding the buoyant force. An object weights 5N and displaces 3.5 N of water when placed in the beaker. The buoyant force is = to the displaced water which is 3.5N. Now, here's where I'm stuck. The volume doubles, and weight stays the same. What is the buoyant force? My guess is that since the volume is doubling, the amount displaced will double so it will be 7N and the object will float because the amount displaced is greater than the weight. Is that accurate?