By: José Maria Tavares
From: CFTC - UL and ISEL
At: Instituto de Investigação Interdisciplinar, Anfiteatro
In this talk, two examples of application of physics to two complex engineering problems will be presented: 1.) Newton's second law, combined with Coulomb friction, will be used to explain some details of the braking of vehicles: the existence of two regimes of braking, the dependence of stopping distance in the number of wheels, the convenience of using a anti-block braking system (ABS), etc. 2.) It will be put in evidence that the differences in conception of jet engines for different types of airplanes can be explained using the 1st law of thermodynamics. In both cases, it will be shown that, using simple and reasonable hypothesis, these complex problems can be made treatable for first year graduate students, showing them in a straightforward manner the power of explanation and prediction of the basic laws of physics.