Hey everybody, nice to be a part of the forum. I needed some help understanding the concepts behind these questions. By correcting the questions answered incorrectly, we get some of the points back. Thanks for any help that I receive. 1. The problem statement, all variables and given/known data Why is it that a fish displaces its own volume AND water? I thought that it only displaces its volume, making it larger to rise and smaller to sink. Why is it that when a large block of wood and a smaller block of iron on weighing scales both register the same weight of 1 ton, the wood has a greater mass, taking buoyancy into account? Why is it that two pennies of the same mass, when one of them is touched with an electrically charged rod, it has slightly less mass than the other one? I thought the proton count in an element had something to do with its atomic mass? Why is it that when a system does work and no heat is added, its temperature decreases? I thought that it increased, and that heat arises when work is done, thus leading to a hotter temperature. Why is it that 100% of of electric energy when sent to a light bulb is converted to heat? Why is it that both the magnitudes and separation distance of two charges makes up the electrical force? 2. Relevant equations Equations aren't really relevant to these questions, more the concepts behind them. 3. The attempt at a solution The attempts are in number 1.