Sección Segunda Del Embargo
II. Cuando teniendo el deudor otros bienes susceptibles de embargo, señale:
A Kazachkov1, M Kireš2
1
V.Karazin Kharkiv National University, Ukraine
2
P.J.Šafarik University, Slovakia [email protected]
Abstract. Hands-on science activities have
an unrivalled potential to help students develop their creativity and critical thinking, provided they are practiced in a minds-on, inquiry-based fashion. Another advantage of the hands-on approach is the extra motivation and professional progress of the teachers.
Examples are reviewed of successful practicing hands-on science in various academic environments.
Mostly low cost experiments in Physics, those activities were supported with computer and advanced multimedia tools when justified.
Transformation of entertaining Physics tricks and Physics toys into highly instructive educational projects required from the students and their instructors much of an alternative viewpoint. Examples of students’ spontaneous observations and creative solutions are given.
Keywords. Multi-disciplinary students projects, hands-on and minds-on educa- tional experiments, efficiency of education, development of creativity, development of critical and alternative thinking.
1. Introduction
Development of students’ creativity and critical thinking is among the priorities of modern education. A presented series of low budget experimental activities is focused on the transition from the involving hands-on activities to the creative and instructive minds-on projects. Reported examples of class demonstrations/labworks and students’ educational research have been practiced in various academic environments with a lot of positive feedback.
Although included experiments are technically in the frames of the university Introductory Physics course and courses of Physics at basic and high school, their analysis often involves and improves knowledge of Mathematics, Biology, Physiology, Chemistry, Engineering Design, skills in logics, arts and team work.
For every observed phenomenon the model is looked for and suggested. The check/proof of the model and comprehension of its predictions is the key point of those creative activities. Solutions of many the presented experimental problems are definitely counter-intuitive, which supports the improvement of critical thinking of the students.
Computer multimedia, including video- measurements, is used in the presented activities wherever appropriate. Incidental observation of Physical phenomena on the Internet is another efficient application of modern technology.
Open-ended by nature, reported activities leave place and imply for their further development by the practicing teachers and students. Importantly, not only the teachers get additional professional motivation when mentoring hands-on projects. The students’
parents may also gain a lot when involved into their kids’ creative activities.
Not the least it is necessary to notice that critical thinking is regarded as a positive alternative approach to either solve a perplexing problem or to cast a fresh view onto the seemingly obvious phenomena. 2. Advanced multimedia in low-cost
hands-on experiments: Heads-on collisions of real objects
Heads-on collisions, being the basic material of any introductive Physics course, are also perfect for the creative students’ projects. Inspirational video-presentation of Mats Selen [1] could be recommended for the starter. Arguably the most impressive demos of the series are those of elastically colliding bodies not touching during the collision. That is achieved by placing strong magnets onto the dry-ice pucks sliding on (effectively above) a smooth surface.
Detailed computer-based studies of bouncing of a single elastic ball off the horizontal surface are performed in [2]. There, account of different mechanisms of energy dissipation sufficiently improved fitting of model dependences to the observed motion of the ball.
Step next in the thrilling inquiry-based studies of elastic collisions could be an arrangement of several colliding bodies (Newton’s Cradle is an example).
Impressive result of multiple collisions of the balls comprising the Astroblaster toy are explained in terms of conservation of momentum [3]. The important role of the coefficient of restitution is demonstrated in ideal and real cases. Real-life experimental results may be compared with a computer model of the toy represented by an
interactive Java applet. Same mechanisms account for the no less impressive behaviour of the stack of two balls dropped onto the solid floor; see Fig. 1 and Fig. 2. Right halves of the figures show the highest elevation of the upper ball after the collision.
Figure 1. A basketball and a touching smaller rubber ball dropped onto the floor Parameters of the experiment were chosen to provide for the upper ball (encircled in the figures) rise only slightly above its initial position after the collision with the lower one, Fig. 1.
Keeping in mind that the duration of the lower ball’s encounter with the floor is about
an initial shift between the basketball and the upper ball. That was supposed to let the balls meet heads-on at the maximum (opposite) velocities to guarantee higher rise of the upper ball. This suggestion is proved experimentally in a very impressive way (Fig. 2).
Figure 2. A basketball and a smaller rubber ball dropped simultaneously onto the floor
with some initial distance between them
More critical approach requires the realistic model of the motion of dropped and colliding balls to account for the different conditions of air resistance acting on the upper and lower balls. Indeed, the basketball efficiently screens the upper ball which as a result moves faster and experiences an additional mid-air collision, revealed by a fast camera video. This is a nice example of the totally justified use of an advanced technology in an essentially low-cost hands-on experiment.
3. Importance of creative students’ observations
All around themselves students may observe intriguing, often incredible phenomena of nature proving that thrilling Science, Physics in particular, is not hidden in the lab; it is literally everywhere.
Inspired by a success of the project [5] we collected creative observation of our students interested in shadows.
It is also very instructive to capture ‘incidental’ Physics episodes that were not supposed to be. An excellent example of an occasional Physics toy, the famous tippie- top [6, 7] could be watched on YouTube [8]. Certainly, that video clip was uploaded not for the sake of the background Physics of it. Characteristically, involved football stars appreciated only the absurdity of the incidentally torn ball reshaping into a sort of a spinning dumb-bell. Although tippie-top sort of behaviour is obvious there.
More interest towards Physics, specifically, to the equilibrium of coupled forks ([9], p.81), is displayed by the creators of the ‘Rieka’ videoclip [10]. They must have included this demo on purpose, with some additional meaning implied. Not going deep into
psychology, we present some ultimate versions of the old nice forks&toothpick demonstration (basic idea courtesy of Abraham Salinas).
4. Acknowledgements
Creative contribution of our students is highly appreciated. This work is the result of the project implementation: Research and Education at UPJŠ – Heading towards Excellent European Universities, ITMS project code: 26110230056, supported by the Operational Program Education funded by the European Social Fund (ESF).
References
[1] Selen M. The Whys Guy™ Video Clip Archives. 4/16/2003
Clip 1 - Inelastic collisions: air-track, mouse-trap, big/small pendulum. http://www.hep.uiuc.edu/home/mats/WC IA/wcia_030416_1.wmv [visited 1-May- 2014]
Clip 2 - Elastic collisions: air-track, Newton's Cradle, billiards, dry-ice pucks. http://www.hep.uiuc.edu/home/mats/WC IA/wcia_030416_1.wmv [visited 1-May- 2014]
[2] Heck A, EllermeijeU 7 .ĊG]LHUVND E. Striking Results with Bouncing Balls. In: C.P. Constantinou & N. Papadouris (Editors), Physics Curriculum Design, Development and Validation, Proc. of GIREP 2008; Nicosia: University of Cyprus; 2009: 190–208.
[3] Kireš M. Astroblaster – a fascinating game of multi-ball collisions. Physics Education 2009; 44 (2): 159–64.
[4] De Izarra C. Duration of an elastic collision. European Journal of Physics 2012; 33 (4): 997–1006.
[5] Noversa S, Abreu C, Varela P, Costa MFM. Investigate the Shadows of Objects: a Pedagogical Intervention Project with Primary School Children. Proceedings of the 10th International Conference on Hands-on Science. Costa MF, Dorrío BV, Kireš M (Editors); 2013, 1-5 July; Pavol Jozef Šafárik University, Košice, Slovakia: 115-20. [6] Pliskin WA. The tippie top (topsy-turvy
top). American Journal of Physics 1954; 22(1): 28-31.
[7] Gray C, Nickel BG, Constants of the motion for nonslipping tippe tops and other tops with round pegs. American Journal of Physics 2000; 68(9): 821-28. [8] A spontaneous football tippie-top. Ball
platzt beim Spiel Bayern München - FC Köln.
https://www.youtube.com/watch?v=fvuky EOwZsM [visited 3-May-2014]
[9] Gardner M. Entertaining Science Expe- riments with Everyday Objects. New York: Dover; 1981.
[10] Müller R: Rieka video clip
https://www.youtube.com/watch?v=Bp94 l2suxqg [visited 3-May-2014]