Forward-to-backward transition of the direction of motion of a projectile launched against horizontal wind is analyzed. For linear drag force, the entire solution, including the expressions for the time-variation of velocity components and the shape of the trajectory, can be derived in closed form. For quadratic or more general nonlinear drag force, the results can be obtained only numerically, because the governing coupled differential equations of motion do not allow an analytical solution, although there is a closed-form relationship between the velocity and an appropriately defined angle parameter in the case of quadratic drag. The analysis of wind-influenced projectile motion in the case of linear and nonlinear (quadratic or nonquadratic) drag force is reviewed. It also favors a deeper discussion about the role of laws, models and hypotheses in the physical sciences, which could be particularly interesting in the case of teacher education. This proposal reconciles the laboratory with Information and Communication Digital Technologies (ICDT). Realizing that the resistive force can be interpreted as the kinetic friction force, according to Amontons' laws, it is possible to build a theoretical model able to predict the trajectory through a first order numerical method, and then _t its parameters to the observed trajectory.
#Projectile motion with air resistance manuals#
All the images and laboratory manuals can be accessed at. The resulting set of images was used to analyse the dynamical evolution of the system,īy recording the coin positions at known instants.
#Projectile motion with air resistance code#
The video frames were separated and each one was assigned a time code by a computational process. We used a video of a two-dimensional real motion of a coin sliding on an inclined plane, a case where the net force varies continuously. It is directed at an intermediate physics course, with the aim of contextualizing the teaching of the laws of friction and empirical modeling in Classical Mechanics. The experiment with images described here contributes to the scarce literature about the experimental approach to the classical problem of oblique launching on the surface of an inclined plane.