# Direct Measurement Video of Einstein riding the Graviton

#### Summary

## Learning Goals

Students will:

- Practice developing a method for solving a problem.
- Practice applying Newton's Laws in two dimensions
- Practice applying circular motion concepts, such as angular velocity and centripetal acceleration

- Practice making measurements from a Direct Measurement Video
- Practice developing an experimental design.

## Context for Use

This activity is intended for introductory physics students who have had some experience with Direct-Measurement Videos and with using Newton's laws to analyze circular motion. For an introduction to using Direct-Measurement Videos for circular motion, see Measuring the Velocity of a Roller Coaster activity.

This activity is also intended for students to learn experimental design. This can be assigned as a homework problem, or as an in-class activity for a whiteboard problem solving session.

## Description and Teaching Materials

There are two parts to this activity. First, students use the video to answer the question, "What is the coefficient of static friction between Einstein and the vertical wall?" The worksheet shown here is a highly scaffold-ed set of instructions. Ideally, students will need far less instruction. For the second part, ask students to develop a method to determine the coefficient of kinetic friction. Specifically, ask students to say what calculations they would do, and what measured values they wold need from the video. For example, if they say that they would need to know the mass of the Einstein action figure, they should show how that would be included in their calculations for the coefficient of friction. One value the students' methods may require is the vertical distance Einstein slides down the vertical surface. Based on the video, students can use the value 5.8 cm. More detailed instructions are included here:

Einstein on the Graviton video page contains all the available file types for this video.