If I submerge a cup in a graduated cylinder filled with water, will the change of the water line show me the volume of the cup? Or is this not the case? I am in an argument with a friend, he believes that the volume of the cup could be found by holding the top of the cup right about the water line(in other words, not allowing any water to enter to the cup) and then measuring the change of the water line. I argued that if one uses this method of measurement, that the change in the water line now includes the volume of the air that is inside of the cup. The scientific definition of volume I found is the amount of space an object takes up. In the 1st experiment I proposed, I believe this finds the amount of space the cup takes up. In the 2nd experiment, I believe this finds the amount of space the cup takes up+the amount of space the air inside of the cup takes up. Am I correct, or is the 2nd experiment actually the correct method for measuring the volume of a cup?