AP/College

Lissajous Introduction

Lissajous patterns have fascinated physics students for decades.  They are commonly observed on oscilloscopes by applying simple harmonic functions with different frequencies to the vertical and horizontal inputs.  Three examples are shown in Figure 1.  From left to right, the frequency ratios are 1:2, 2:3, and 3:4.  These Lissajous patterns were created by use of the parametric equation section of The Grapher software written by the author of this lesson.  You are welcome to use this softwa

A Physics Challenge

In this lesson, AP and college students are challenged to derive equations for the periods of two fundamental modes of oscillation of a pair of coupled physics carts.  Derivation will involve Hooke's law, Newton's Second Law of Motion, and principles of simple harmonic motion.  Theory is then compared to experimental results obtained from PocketLab Voyager rangefinder data using Phyphox software.

Introduction

In this lesson students will find that a current-carrying loop can be regarded as a dipole, as it generates a magnetic field for points on its axis.  Students use PocketLab Voyager and Phyphox software to compare experiment and theory for the magnetic field on the axis of a current loop.  A similar experiment not making use of Phyphox can be found by clicking this link.  An experiment making use of a magnet, instead of a

Isaac Newton

Isaac Newton is well-known for the apple that hit his head and the discovery of gravity.  His three Laws of Motion, however, are among the most famous laws of physics.  In this lesson, we are especially interested in Newton’s Third Law of Motion—all forces between two objects are equal in magnitude and opposite in direction.  We will be studying collisions between two identical carts that are bouncing back-and-forth, much like a Newton’s cradle with just two steel balls.  Repelling magnets attached to the front bumpers of each of the carts al

Introduction

Magnets, from the traditional alnico bar magnets to the modern neodymium magnets, have been of interest to most everyone for decades. The attraction or repulsion of two such magnets when brought close together is particularly interesting. This can be expressed by making quantitative measurements relating magnetic field strength to distance from the magnet.

Introduction to Accelerometers

What does an accelerometer measure? The obvious answer is acceleration, but that's not really true. An accelerometer actually measures normal force or restoring force which we equate to acceleration using the formula, F=ma. This article will explain the fundamental operating principles of accelerometers and answer the question: how does an accelerometer work? We will also investigate the capabilities and drawbacks of accelerometers in certain applications.

You can investigate these concepts on your own using:

In the study of collisions between two carts, it is desirable to collect position data for both carts.  This can be done with a pair of Voyagers, each connected to separate devices running the PocketLab app. Starting data collection on both Voyagers by simultaneously clicking data recording on both PocketLab apps is difficult.  One cannot view the data on a single device in real time, and analysis of data requires combining data from two separate devices.

It would be nice if one could connect two (or more!) Voyagers to the same device—say to an Android device or an iOS device running an app that could display concurrent data collection from both Voyagers.  Such a capability is possible by the use of Phyphox (physical phone experiments), an app developed at the 2nd Institute of Physics of the RWTH Aachen University in Germany.  The author of this lesson has been working with a pre-release Android version of this app that supports BLE (Bluet

What Internet of Things projects are Stanford students developing? Stanford ME220 "Introduction to Sensors" is an introduction to the variety of sensors that are used in engineering practice. Students in this class get a comprehensive overview of common practices with sensors and learn the direction in which sensor technologies are heading.