Students study the Atwood machine to verify Newton’s Second Law of Motion. In this machine, two hanging masses are tied to the end of a string that loops around a pulley. The larger mass then moves downward with a constant acceleration, while the smaller mass accelerates upward. The magnitude of this acceleration is a quantity of great interest as it relates to the values of the two masses. In this lesson, an Atwood machine is constructed using parts from LEGO®’s Simple & Powered Machines Set<
A novel activity that demonstrates one of the effects of a microgravity environment. In this exercise, the structure of a flame is filmed while simultaneously plotting the acceleration of the system as it is released and experiences freefall. The apparatus is low-cost, possibly using only scrap materials found in the classroom. A PocketLab One is paired with a smartphone and used to collect the data. Conceptually, the exercise is straightforward, though considering noise in the data, limits of the system, and chemistry applications could easily enrich the content.
PocketLab sensors can measure the pressure in a fluid line easily, by putting the PocketLab into a plastic wash bottle. (For protection, put the sensor in a ziplock bag with a paper towel.) The wash bottle nozzle inserts easily into 1/4" ID tubing, and can be used as a pressure tap to measure fluid pressure in two different T junctions.
PocketLab sensors work very well for measuring air and fluid pressure. To protect them, I have students seal them in a ziplock bag along with a paper towel (which absorbs any water that leaks in, keeping the sensor innards dry).
The attached lab worked very well to demonstrate the relationship between fluid column height and hydrostatic pressure. The hardest aspect is modifying the 5 gallon jug by mounting a nozzle connector to its side. It took dexterity, patience, and lots of silicon caulk.
A widely used experiment for studying Newton’s Second Law of Motion makes use of a Half-Atwood machine. In this experiment a cart on a horizontal surface is tied to a mass hanging over a pulley. Upon releasing the hanging mass, the cart begins to accelerate. The magnitude of this acceleration is a quantity of great interest as it relates to the amount of the hanging mass. In this lesson, a Half-Atwood machine is constructed using parts from LEGO®’s Simple & Powered Machines Set. Voyager is moun
A very popular air disk is the Air Power Soccer Disk, available at a variety of locations including Amazon, Walmart, and Educational Innovations, Inc. at prices ranging from about $5 to $17. Powered by four AA batteries, it rides on a cushion of air on any reasonably smooth surface. While kids love to kick it around like a soccer ball, it is also a great companion for PocketLab Voyager when studying physics principles. In this lesson, students quantitatively investigate the deceleration of an air disk as it
A thermoelectric generator (TEG) is a device that converts temperature differences directly into electrical energy. In the past several years, there has been a great deal of research in the use of TEGs to recover electrical energy from waste heat produced in a variety of systems. As a result of this research, the study of thermoelectric generators in physics and engineering curricula is well worth including in NGSS-based coursework.
A French watchmaker and physicist, Jean Charles A. Peltier, observed that electric currents produce heating or cooling at the interface between two dissimilar metals. This is now known as the Peltier effect and is used in numerous cooling applications, including air cooling of small refrigerators, beverage cooling in camping, cooling of electronic components, extraction of water in air by dehumidifiers, and cooling of CCDs in telescopes, spectrometers and cameras.
The physics of the sounds produced by music boxes is definitely worth studying in curricula based upon NGSS (Next Generation Science Standards). The prongs of a metal music box comb and an oscillating meter stick that overhangs a table are both examples of cantilevers--long projecting beams that are supported only at one end. Other common examples include many suspension bridges, beams that support balconies on high rises, diving boards, airplane wings, and flagpoles mounted to the side of a building.