## Maryland Open Source Tutorials in Physics Sensemaking

developed by Rachel E. Scherr and Andrew Elby

Thank you for your interest in the Maryland Open Source Tutorials in Physics Sensemaking! Instructors inevitably need to adapt even the best reform materials to suit their local circumstances. We offer a package of research-based, open-source, epistemologically-focused mechanics tutorials, along with the detailed information instructors need to make effective modifications and offer professional development to teaching assistants. In particular, our tutorials are hyperlinked to instructor's guides that include the rationale behind the various questions and advice from experienced instructors. There are video clips of students working on these materials in Periscope: Looking into learning in best-practices physics classrooms, a collection of classroom videos for faculty and TA/LA professional development. Our materials thus facilitate their own implementation and develop instructor expertise with PER-based instructional materials. You can find more details on the Open Source Tutorials teaching method page on PhysPort, or in the welcome and overview document below.

### 00 Welcome and overview

The attached document describes the materials and how to use them.

### 01 Position and velocity

By walking in front of an MBL motion detector and seeing the resulting position and velocity graphs in real time, students explore the notions of position and velocity and the common confusions that arise between the two. Students think more systematically about the relationship between the two kinds of graphs for a given motion, and about the notion of coherence (“your different bits of knowledge must not only make sense individually but also fit together”).

### 02 Velocity and Acceleration

By rolling carts in front of the motion detector and seeing the resulting velocity or acceleration graph in real time, students begin to explore how the concept of acceleration differs from velocity. For a cart rolling up and down a ramp at the moment it reaches the peak: What’s going on with the acceleration at that moment? And do we have to simply accept the experimental result or can we make sense of it intuitively?

### 03 Newton's second law

(Tutorial) By considering a child being pulled out of a well by a rope, students reconcile Newton’s 2nd law with the intuitive idea that the rope’s force must “beat” the downward force of gravity even when the child is moving at constant velocity. (ILD) By showing students that a desktop compresses in response to a book sitting on top of it, and by activating their intuitions about the push provided by a compressed spring, this worksheet helps students see the seemingly-passive normal force as an active push, just like any other force.

### 04 Newton's third law

Considering a big truck crashing into a parked car, students try to reconcile Newton’s 3rd law with the intuitive idea that the car “reacts” more during the collision and therefore appears to feel a larger collision force than the truck feels. This lesson clarifies the notion of refining intuition as an alternative to jettisoning common sense.

### 05 Free body diagrams

(Tutorial) This lesson helps students see that a free-body diagram is useful sense-making tool (as opposed to “something I’m required to draw”) when analyzing multi-object interactions. The tutorial also addresses common conceptual difficulties regarding transmitted forces. (ILD) Addresses common conceptual confusions associated with the kinematics and dynamics of circular motion.

### 06 Momentum

By building upon their intuitions about the “oomph” of a moving object, students “guess” the formula for momentum, and for momentum conservation. They then refine that formula (to take directionality into account) and practice using it.

### 07 Work and energy

(Tutorial) Introduces kinetic and potential energy and their relation to work. Addresses a common conceptual confusion by helping students make a crucial distinction between doing work (exerting a force over a distance to give another object energy) and expending energy (e.g., pushing fruitlessly against a brick wall). (ILD) After helping students to see that a spinning object has kinetic energy even if it’s not going anywhere, the worksheet helps students explain why a sliding piece of dry ice beats a rolling ball (or disk) in a race down an inclined plane.

### 08 Pressure

(Tutorial) This lesson helps students understand how pressure at various points in a container of liquid depends on depth, while addressing some common conceptual confusions about pressure. (ILD) This lesson helps students reconcile the fact that metal and wood in the same room share the same temperature with the fact that the meal feels colder.

### 09 Torque

This tutorial emphasizes the common-sense basis for certain physics equations – in this case, the balancing equation for weights hung from a rod balanced on a pivot (e.g., W1d1 = W2d2) and the related equation for torque. Students use these common-sense-based equations to account for balancing multiple objects at different distances from the pivot and, eventually, balancing extended objects.

### 10 Pulses

This tutorial emphasizes the development and use of a mechanistic model in the context of wave pulse propagation. The tutorial first has students recognize a factor that does not affect the speed of travel (though many students think it does): the nature of the wrist-flick that produces the pulse. After recognizing what is right about their intuition (and what isn’t), they spell out a mechanism for wave pulse propagation and use it to explain what they have observed.

### 11 Electrostatics

The main goal of this tutorial is for students to come up with a model for how objects become charged or uncharged. Along the way, they use a common representation for charge and make a variety of observations.

### 12 Electric fields

The main goal of this tutorial is for students to recognize and make good use of a familiar experience (the wind from a fan) in coming to understand a relatively abstract concept (electric field). The tutorial emphasizes the differentiation of force and field, first with kites and then with electric charges.

### 13 Electrostatic potential

This tutorial, like the one on electric fields, uses a mechanical context as the basis for developing ideas that are then applied in electrostatics contexts. Students develop the idea of potential by applying the work-energy theorem, first in a non-uniform gravitational field and then in various electrostatic situations.

### All Tutorials

Download the entire set of tutorials, ILDs, pre-tests, post-tests, and instructors guides as a zip file