People are able to float in water, because they have a density just lower than water.
Fruit and vegetables usually just float or just sink, depending on how dense they are. In a big bowl or bucket of water, try some floating and sinking experiments. Apples and oranges float, but carrots and tomatoes sink. Things which are dense tend to sink - you may be surprised by which are the densest. Carefully poke the paper down, lift it out, and leave the paper clip floating.