The Frictional Force of Air on a Vertically Moving Object Without Initial Velocity Nani Yuningsih (a*), Sardjito (b)
a) Department of Refrigeration and Air Conditioning Engineering, Politeknik Negeri Bandung, Bandung 40012. Indonesia
*nani.yuningsih[at]polban.ac.id
b) Department of of Electrical Engineering, Politeknik Negeri Bandung, Bandung 40012
Abstract
One popular mechanical concept studied both theoretically and experimentally is the motion of vertically falling objects due to the influence of gravity with no initial velocity, either called free-fall motion or falling motion against air friction. This study aims to apply the concept of vertical motion of objects that rub against the air to determine the appropriate formulation for the fluid friction force. Theoretical analysis is carried out by considering the presence of a frictional force of air against the falling object. Data analysis is conducted by matching mathematical solutions to experimental data. Experimental data collection was carried out using an automatic free-fall motion device. Experimental data observed is the altitude or distance traveled and travel time. The model studied concerning this air friction force is the air friction force that is directly proportional to the velocity and the one which is directly proportional to the square of the velocity. The result shows that, for a small-sized object with the order of centimeters and zero initial velocity, the corresponding model is the friction force directly proportional to the square of velocity.
Keywords: vertical motion, air friction, fluid friction
