AP/College

Introduction to Hysteresis

Hysteresis can be defined as a lag time in the response of a system to forces placed on the system.  The response of the system depends not only on the present magnitude of the force but also on the previous history of the system.  From the point of view of mathematics, the response to the force is a double-valued function.  This means that one value applies when the force is increasing, while another value applies when the force is decreasing.  A graphical plot of force and re

Introduction to Pressure Sensors

Pressure sensors are one of the most widely used sensors and can be found in probeware for lab measurements, but more commonly in billions of devices including smartphones, wearables, automobiles, drones, weather centers, and medical instruments. Pressure sensors were one of the first sensors to be miniaturized and mass produced at a low cost through microelectromechanical systems (MEMS) fabrication.

Rotational Motion and Moment of Inertia Lab Setup

Figure 1 shows a ramp and three distinctly different objects that you will release from rest at the top.  Each object will roll downward to the end of the ramp without slipping, resulting in rotational motion.  The roll of Gorilla tape has a shape known as an annular cylinder.  The can of jellied cranberry sauce is a solid cylinder.  The cardboard tube, in contrast to the can, is hollow.  All three of these objects will rotate about their central cylinder axis while rolling down the ramp.  Each of these three objects has a

Newton's Law of Cooling

In this experiment students will use PocketLab Voyager to collect data related to the cooling of a container of hot water as time goes on.  Sir Isaac Newton modeled this process under the assumption that the rate at which heat moves from one object to another is proportional to the difference in temperature between the two objects, i.e., the cooling rate = -k*TempDiff.  In the case of this experiment, the two objects are water and air.

Introduction

In a PockeLab lesson entitled "Hydrostatic Pressure Lab", posted by kwarnke in October 2017, students investigate the relationship between the height of a column of water and hydrostatic pressure.  The lab results worked very well in this regard, but the apparatus uses a 5-gallon jug with modifications, a bicycle pump, and 5 meters of vinyl tubing.  We should be able to come up with a much simpler and less expensive fluid pressure apparatus to achieve the same result, as the

Terminal Velocity Introduction

The effect of mass on the terminal velocity of an object falling in air is commonly done using basket coffee filters.  But how could we study the effect of area on the terminal velocity of a falling object?  One way to do this is to use PocketLab Voyager and its range finder along with a single piece of cardstock as the object to be dropped.

Introduction

What can you do with a PocketLab Mini HotRod, Voyager, five pieces of HotWheels track, and a half-dozen wood blocks about the size of Jenga blocks?  How about an experiment in energy conservation!  Add CloudLab and you have an environment for your students/lab groups to perform, analyze, document and save their PocketLab lab reports.

This might be an interesting  physics PocketLab study!  Good for the human body, or not so good?

What is hysteresis?

Hysteresis can be defined as a lag time in the response of a system to forces placed on the system.  A common way used in physics classes to observe hysteresis is by loading and then unloading weights from a suspended rubber band, while observing the extension of the rubber band.  Students find that the rubber band does not Obey Hooke's law.  They also observe that the amount of stretch of the rubber band is different when unloading than when loading.

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.