Waves and Simple Harmonic Motion

Light travels in waves, but unlike waves on the ocean, they are much too small for us to see with the naked eye. A polarizer is a light filter that only allows light waves that are moving in one direction to pass through, letting us indirectly observe some of the wave properties of light. This aligned light that passed through a polarizer is called polarized light.
 

Introduction

Don't discard your school's empty 3D filament reels.  There's a good chance that you and your students could come up with some interesting physics lab investigations using these reels.  Attach Voyager or PocketLab One to the reel and the possibilities are endless!  This lesson describes a unique experiment in which periodic motion is investigated using an empty 3D filament reel.  Depending on the teacher's goals and amount of detail in the analysis of collected data, this lab could be used from the 4th grade through high school.  The

Introduction

Periodic motion is motion that repeats itself in regular intervals.  If the motion has characteristics that are sinusoidal, then the motion is said to be simple harmonic (SHM).  In this lesson, periodic motion that is not simple harmonic is studied.  Never-the-less, the motion shows many characteristics of SHM, as can be seen when studying the position, velocity, and acceleration graphs.  This lab makes use of PocketLab Voyager that has hitched a ride on an "intelino® smart train" and is running on the VelocityLab app.  Int

Introduction

Damping causes oscillatory systems to dissipate energy to their surroundings.  Frictional losses are quite common in mechanical systems and result in damped simple harmonic motion.  For example, when a child stops pumping a swing, the amplitude of the oscillations gradually decay toward zero.  The same thing happens to a mass that hangs from an oscillating spring.  It is quite common for the amplitude of such oscillations to exhibit a behavior that is negative exp

Introduction

Damping causes oscillatory systems to dissipate energy to their surroundings.  Frictional losses are quite common in mechanical systems.  For example, when a child stops pumping a swing, the amplitude of the oscillations gradually decay toward zero.  The same thing happens to a mass that hangs from an oscillating spring.  It is quite common for the amplitude of such oscillations to exhibit a behavior that is negative exponential over time, as shown in Figure 1.  The graph indicates that if we take the amplitude at time t=0 to be 1, then the amplitude at time

The PocketLab Voyager Swing

The PocketLab Voyager swing, 3D printable from the accompanying .STL file, offers your physics students a way to study a plethora of physics concepts in a single experiment. Figure 1 shows a closeup up the swing, approximately 5½ inches tall, 1¾ inches wide, and 1¾ inches deep.

Introduction

In a well-known 1938 book entitled "Demonstration Experiments in Physics", editor Richard Sutton describes a device that produces simple harmonic motion (SHM) mechanically.  With today's tremendous growth in the 3D printing industry, such a device can now be easily constructed for classroom demonstrations of SHM.  Couple this device with PocketLab Voyager and you can obtain real-time graphs describing the motion.

Introduction to Rangefinders

Rangefinders, sometimes called motion sensors or motion detectors are commonly used in probeware, camera autofocus, and robotics. Rangefinders operate on the principle of a time-of-flight measurement and consist of a transmitter and receiver. The transmitter emits a signal (ultrasonic or optical) then the receiver detects the reflection or echo of the signal. The amount of time between transmit and receive is called the time-of-flight and is used to calculate the distance to the reflecting object:

This 3D printed model demonstrates the physics of a simple pendulum that consists of a mass, m, hanging from an arm of length, L, and fixed at a pivot point, P. You can move the mass along the length of the arm to change the center of mass of the pendulum. If you displace the pendulum from equilibrium to an initial angle, θ, and release, the motion will be regular and repeat. This is an example of periodic motion also called simple harmonic motion.

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