Although
a raindrop has been illustrated as being pear-shaped or tear-shaped, high-speed
photographs reveal that a large raindrop has a spherical shape with a hole not quite
through it (giving it a doughnut-like shape). Water surface tension pulls the
drop into this shape. As a drop larger than 0.08 inches (2 millimeters) in diameter
falls, it will become distorted. Air pressure flattens its bottom and its sides
bulge. If it becomes larger than 0.25 inches (6.4 millimeters) across, it will
keep spreading crosswise as it falls and will bulge more at its sides, while at
the same time, its middle will thin into a bow-tie shape. Eventually in its
path downward, it will divide into two smaller spherical drops. (The Handy
Science Answer Book, compiled by the Science and Technology department of the
Carnegie Library of Pittsburgh)
Although
a raindrop has been illustrated as being pear-shaped or tear-shaped, high-speed
photographs reveal that a large raindrop has a spherical shape with a hole not quite
through it (giving it a doughnut-like shape). Water surface tension pulls the
drop into this shape. As a drop larger than 0.08 inches (2 millimeters) in diameter
falls, it will become distorted. Air pressure flattens its bottom and its sides
bulge. If it becomes larger than 0.25 inches (6.4 millimeters) across, it will
keep spreading crosswise as it falls and will bulge more at its sides, while at
the same time, its middle will thin into a bow-tie shape. Eventually in its
path downward, it will divide into two smaller spherical drops. (The Handy
Science Answer Book, compiled by the Science and Technology department of the
Carnegie Library of Pittsburgh)