Experimental analysis of ice friction in the sport of bobsleigh

We report the first derivation of the coefficient of friction between bobsleigh runners and ice from experimental measurements performed in a controlled environment. In a series of experiments on both horizontal ice and a track sloped at 6.80°, a radar gun was used to sample the speed of a moving sled in the range of (1–10) m/s at a sample rate of 31.25 Hz. The acceleration of the sled, and thus the coefficient of friction, was extracted from these data, with a value of (4.2 ± 0.9) × 10^?3 for the coefficient of friction associated with a set of two-man bobsleigh runners. There was no detectable variation in the coefficient of friction with velocity at this range of speeds and experimental accuracy. This result improves our knowledge of this coefficient over currently accepted values determined from indirect measurements, and indicates that the coefficient is lower than the currently accepted range.     

The Habits of Mind Necessary to Generate New Ways of Teaching in a Career of Constant Change

In this paper we explore the philosophy, pedagogy and implementation of the third year course sequence in the M.A. in Educational Technology program at Michigan State University. We discuss how “little-r” revolutions in teaching and learning, i.e., technology facilitated revolutions specific to individual classrooms and contexts, are used to introduce our students to the thinking patterns of designers and innovators. This is accomplished by an overlapping emphasis on learning by design, trans-disciplinary creative cognitive tools, innovative technology, and reflective practice. In this environment, we also transition our students from acting as consumers of educational media to being producers of educational experiences. That is, not only do the students construct new educational media, they consider the aesthetic and affective implications of technology use for teaching and learning. Finally, given the rapid evolution of educational technologies, we support students as they establish a foundational vision for the interplay of education and technology that will serve them into the future, as they, and their learners, adapt tonew and emerging digital environments.