An object whose density is Pob falls from a certain height into a liquid whose density is pliq In the figure the potential energy `W` of the object is plotted along the vertical axis and the position of the object (its altitude) is plotted along the horizontal axis. The potential energy of the object at the level of the liquid is taken zero and the positive direction of the vertical axis (the `W` axis) is the one pointing upward from the liquid's surface. Determine which of the five straight lines, `1-5`, corresponds to an object with the highest density and which to an object with the lowest density. Is there a straight line among these five for which `Pob = (112) Pliq` ? The arrows on the straight lines point in the direction of motion of the object.