The variables for this experiment include mass, volume and the materials in the various balls, as well as their densities. In Part II, you will be comparing an inflated football with a deflated one. Use the drop-down menus to complete the sentences and identify the independent and dependent variables. In Part II, the independent variable, the one that is intentionally manipulated, is . (mass, volume, material, density) In Part II, the dependent variable, the one that you measure the response in, is . (mass, volume, matierl, density)