Free Fall Time Measurement Using a Smartphone

Abstract: In this paper a way to measure free fall time is described. Free fall is the linear smoothly accelerating motion of a body when we let it fall from a height and the only force acting on it is its weight, which is considered constant. Air resistance is considered negligible. Free fall takes place accurately only in a vacuum. The free fall time is measured with the help of a smartphone application that includes an acoustic timer. The purpose of this paper is to show that in natural science courses of the secondary education high cost and not easy to use devices can be replaced with sensors that have smartphones.

Key words: smartphone, phyphox, acoustic timer, free fall, gravity acceleration