A simple and effective magnetic dynamometer to teach Newton’s third law

Abstract

Newton's laws of mechanics are a cornerstone in the development of modern science and its learning can be the very first opportunity for students defy their common sense perceptions and replace them with a more robust world view. However, despite their fundamental importance, many studies demonstrate how difficult is the true comprehension of the basic aspects of Newton's laws. Therefore, any effort to increase the possibilities of teaching them is welcome. It is in this sense that we propose an experimental apparatus to assist teachers in the specific case of the Newton's actionreaction third law. Our system is formed by a pair of dynamometers made from a flexible plastic strip to where small neodymium magnetic disks are attached. Forces are exchanged by means of the magnetic fields and the plastic strip deflection angle indicates the force magnitudes. This is a very cheap, easy to build and effective arrangement, suitable for numerous classes that demand many experimental kits.

Fizik Öğretiminde Manyetik Alan ile İlgili Çalışmaların İncelenmesi: Physics Education Örneği

“…Bunun yanında manyetik alan kavramını içeren ve daha düşük öğrenim düzeylerine hitap eden çalışmalar da dergide yer almaktadır (Bergmann, Dürr & Rockstuhl,2019;Boyle, 2019). Bazı çalışmalardaki deneylerin ise hem lise hem de üniversite seviyesindeki öğrencilere uygulanabileceği belirtilmektedir (Alho, Silva, Teodoro & Bonfait, 2019;Scomparin & Carvalho-Neto, 2018). Bu durumda öğretmenlerin pedagojik alan bilgilerini uygun şekilde kullanabilmeleri devreye girmektedir.…”

The Principle of Action and Reaction According to Newton

“…Particular attention has been paid to the first two laws of motion, whereas there has been less interest in the third law, known as the principle of action and reaction (hereinafter PA) [1][2][3][4][5][6][7]. The reasons could be, on the one hand, the apparent evidence for the principle itself, (There are some difficulties in having a complete understanding of its meaning in pedagogical situations [8][9][10][11]) and, on the other hand, the modest use that Newton made of it in the Principia given that their own mechanics, more precisely its theoretical core, is essentially that of the mass point, while PA is mainly important in the study of systems of interacting bodies.…”