If you drop a rock into a 16 foot well and the rock is traveling 4 feet per second how long will it take the rock to hit the bottom of the well?

Answer 1

4 seconds It will take 4 seconds to hit the bottom of the well. 16 feet divided by 4 feet per second equals 4 seconds. But there are some major caveats. The rock will have to instantly accelerate (by whatever means, whatever force) to its speed of 4 feet per second (fps) as soon as it is released. And the rock will not continue to accelerate due to gravity (or any other force) beyond its fixed speed of 4fps. Be clear about the theoretical nature of the question and be sure to understand what is being set aside in order to arrive at the answer. Don't picture someone standing over a well and dropping a rock, because in the real world, gravity doesn't actually work as an instant accelerator. And, because it is a constant force that is constantly acting on a body, if the body is unsupported, the body will fall, and it will continue to accelerate because gravity is constantly pulling on it.