S. PrasitpongS. RakkapaoR. ChitareeThaksin UniversityPrince of Songkla UniversityMahidol University2018-11-092018-11-092014-01-01Physics Education. Vol.49, No.3 (2014), 271-27413616552003191202-s2.0-84899753691https://repository.li.mahidol.ac.th/handle/20.500.14594/34931We present a bristle tips apparatus devised to help students visualize frictional force directions in dynamic situations simply. © 2014 IOP Publishing Ltd.Mahidol UniversityPhysics and AstronomySocial SciencesArticleSCOPUS10.1088/0031-9120/49/3/271