Many experiments in chemistry and physics require the use of a temperature-controlled water bath.  A favorite experiment in our introductory university physics course, in which the students measure the temperature dependence of resistivity for a coil of copper wire using a Wheatstone Bridge circuit, is one such experiment.  The rise in popularity of sous vide-style cooking has brought inexpensive immersion heater/circulators to the consumer market.  These sous vide cookers can maintain a water bath to within +/- 0.1 degree C from just above room temperature to near boiling.  Previously, our students used hot plates and glass thermometers to set and control the temperatures for this experiment.  We show how replacing the old setup with a sous vide cooker water bath yields consistently better results in student labs, which now reflect the precision of the Wheatstone Bridge measurement.

The Egg Drop project for ALL Eggs is a new twist on a classic HS Physics project. The typical project involves students building a container that holds an egg and protects it from a fall of a known height. Often there are constraints that encourage students to apply their understanding of the impulse momentum theorem. This new twist requires students to design a container that can protect eggs of different sizes. Students learn about the history of gender bias in crash test studies, and recognize social implications of engineering design decisions. Students extend their learning by designing vehicle safety features that protect all people, large and small, male and female. This session will support teachers to learn how to use the engineering design process to explore social justice issues, and to promote equitable practices and culturally relevant teaching in your classroom. This project has been supported by the Knowles Teacher Initiative as part of the Engineering for Student and Community Empowerment project. The Knowles Teacher Initiative is a nonprofit organization that supports a national network of mathematics and science teachers who are collaborative, innovative leaders improving education for all students in the United States.

In my introductory University Physics course, we begin our rotational unit with a missing-energy mystery.  Students roll three different shapes (Pasco’s Rotational Inertia set) down a track and use Excel to create ternary energy diagrams.  These show that the energy is “lost” (transformed) continuously, at a constant fraction that differs for each shape; students are challenged to develop a hypothesis to explain these differences.  This contrasts an earlier example of energy dissipation in dropping coffee filters.  I then deepen the mystery with a demo: I designed and 3-D printed a smooth curve that joins two sloped Pasco aluminum tracks (bottom side up) in a shallow “V”.  A 3-D printer filament spool beautifully rolls up and down these tracks repeatedly, thus showing that not all the “missing” energy is dissipated.  I resolve the mystery the following day in lecture, when I introduce rotational kinetic energy and moments of inertia.

Coupled pendulums sometimes show fascinating phenomena that can amaze laypersons and experts alike. Examples of such pendulums have often been presented. Experimental investigations of mechanical oscillations using smartphone apps have also often been described. Here, I describe an extension of the experimental possibilities that can be realized by an external sensor box (“satellite box”) in connection with the app Phyphox. A suitable application of this satellite box is the direct and simulta- neous recording of angular velocity and vertical acceleration in the Wilberforce pendulum. In this respect, the new experimental idea can be a great stimulus for physics courses at highschool school or even college level.

Three-dimensional thinking is one of the most difficult skills Introductory Astronomy students struggle with. For instance, how one’s latitude on Earth and the declination of the Sun affect the path of the Sun over the course of a day. Typically, we use diagrams, animations and a lot of hand gestures to try to convey these concepts. Here I present a simple 3D model of the celestial sphere that can used in conjunction with 2D representations. This is not a new invention – the traditional name for it is “armillary sphere” – but this version is easy to build, easy to use, large enough to gather a class around, and inexpensive.