Regarding falling pennies, how fast do they fall?
Ron Pelloni, Oak Park
Several people have posed this or similar questions on the subject of fall speeds. Earth’s gravitation causes all objects falling in a vacuum to fall at a constant acceleration of 32 feet per second per second. That is, after one second, the fall speed is 32 feet per second; after another second, the velocity increases to 64 feet per second, then to 96 feet per second after the third second, and so on. However, pennies falling through the atmosphere encounter air resistance that slows their rate of descent until a terminal fall speed is reached. For pennies, that terminal fall speed is attained after only about 50 feet of descent, and is a mere 25 mph.