Student understanding of graph slope and area under a curve: A replication study comparing first-year physics and economics students

The understanding of graphs and extraction of relevant information from graphs plays a major role in physics education and is also important in several related fields. Recently, Susac et al. [Phys. Rev. Phys. Educ. Res. 14, 020109 (2018)10.1103/PhysRevPhysEducRes.14.020109] compared physics and psychology students’ understanding of graphs in the contexts of physics and finance. They showed that physicists scored significantly higher in both domains and that all students solved the slope problems better than the area problems. Moreover, eye-tracking data revealed that physics students spent more time on problems associated with the area under the graph and focused longer on the axis labels of finance graphs, indicating higher cognitive demands. In this eye-tracking study, we aim for a generalization of the results obtained by Susac et al. by comparing physics students to another nonphysics sample, viz., economics students. The findings broadly confirm the results of Susac et al.; that is, physics students perform better than nonphysics students. While economics students likely have better prior knowledge on finance context than psychology students, the physics students still outperform them on the finance questions. In contrast to the work by Susac et al., both groups of students had the same visit duration on the graphs, consequently proving total dwell time to be an inadequate predictor of performance. Instead, we identify that attention on concept-specific areas of interest within the graphs discriminates the correct from the incorrect performers. Furthermore, we analyzed the confidence level of the two student groups and found that physics students have a higher ability to correctly judge their own performance compared to economics students. Overall, our results highlight the importance of an instructional adjustment towards a more mathematical- and graphical-based education

Rosetta Lander - Landing and operations on comet 67P/Churyumov-Gerasimenko

The Rosetta Lander Philae is part of the ESA Rosetta Mission which reached comet 67P/Churyumov–Gerasimenko after a 10 year cruise in August 2014. Since then, Rosetta has been studying both its nucleus and coma with instruments aboard the Orbiter. On November 12th, 2014 the Lander, Philae, was successfully delivered to the surface of the comet and operated for approximately 64 h after separation from the mother spacecraft. Since the active cold gas system aboard the Lander as well as the anchoring harpoons did not work, Philae bounced after the first touch-down at the planned landing site “Agilkia”. At the final landing site, “Abydos”, a modified First Scientific Sequence was performed. Due to the unexpectedly low illumination conditions and a lack of anchoring the sequence had to be adapted in order to minimize risk and maximize the scientific output. All ten instru- ments could be activated at least once, before Philae went into hibernation. In June 2015, the Lander contacted Rosetta again having survived successfully a long hibernation phase. This paper describes the Lander operations around separation, during descent and on the surface of the comet. We also address the partly successful attempts to re-establish contact with the Lander in June/July, when the internal temperature & power received were sufficient for Philae to become active again

Viskositäts- und Kompressibilitätseinfluss in der Strömungsmechanik

Die Kombination von Reibung und Kompressibilität wird bei der Rohrströmung, der Kugelumströmung und der laminaren und turbulenten Plattengrenzschicht untersucht. Das Auftreten von Verdichtungsstößen führt zur Stoß-Grenzschicht-Interferenz und auf den Tsien-Parameter. Die Mach-Reynoldszahl Ähnlichkeit in der Gasdynamik führt zur Abgrenzung der verschiedenen Strömungsbereiche. Resultate von Windkanaluntersuchungen sowie analytischen und numerischen Berechnungen werden für das Rhombusprofil und das NACA 0012 Profil analysiert