1. A. Sarges Guerra1,2,3, D. Del Greco1,2, J. Farina1
Determination of the coefficient of restitution using the digital camera.
A. Sarges Guerra1,2,3, D. Del Greco1,2, J. Farina1
1Facultad Regional Rosario - Universidad Tecnológica Nacional (ARGENTINA)
2Escuela Secundaria Modalidad Técnico Profesional Nº 466 (ARGENTINA)
3Escuela Secundaria Modalidad Técnico Profesional Nº 485 (ARGENTINA)
Año:2019
ABSTRACT:
This work presents a didactic proposal for determining the coefficient of restitution of a ping pong ball by performing a practical work.
Information and communication technologies (NTIC´S) are part of our day to day. The low cost of digital cameras, in the market, as well as cell phones, makes these devices available to almost all of our students. Experimenting with the possibilities that these tools provide us and learning their management is an important ally in the significant learning of some educational topics.
INTRODUCTION.
Information and communication technologies (NTIC´S) are part of our day to day. The low cost of digital cameras, in the market, as well as cell phones, makes these devices available to almost all of our students. Experimenting with the possibilities that these tools provide us and learning their management is an important ally in the significant learning of some educational topics.
The cell phone or the digital camera represent another resource in the classroom to observe, acquire knowledge and communicate. Its use with the complement of the software suitable for the edition and treatment of image, makes this tool a powerful means to obtain and record data.
OBJECTIVE.
That students develop cognitive and procedural skills that can later be transferable to other experiences of their learning.
METODOLOGY.
We propose in this work the recording of a video of a few seconds and then extract by using the free software TRACKER the parameters that govern the movement of a ping pong ball and perform an analysis of them, and finally calculate the value of the coefficient. The most important thing is not the intensity of the images but the resolution of them. Keep in mind that lighting should be adequate to avoid shadows that lead to poor results in the determination of parameters.
In addition to the parameters obtained, the software offers a wide range of options in the form of tables and graphics.
RESULTS.
The implementation of the proposal was made in the course of Physics I in the Chemical Engineering career. From the reports prepared by the students, it can be observed that they have managed to fulfill the proposed activities.
According to the regulations of the International Table Tennis Federation, a ball with a diameter of 40 mm and a mass of 2.8 g should be used for the game, which when dropped from a height of 30 cm should reach 23 cm after the first rebound , this corresponds to a coefficient of restitution of The ball used for this experience has a diameter of 38 mm and a mass of 1.95 g. The data obtained were extracted using the TRACKER software:
1º Máximo: 99,1 cm
2º Máximo: 65,8 cm
3º Máximo: 46,0 cm
4º Máximo: 33,5 cm
With this data they calculate the coefficient
CONCLUSIONS.
Tracker is free software that allows the analysis of movements (and other real situations) in one and two dimensions. The program allows us to extract in tables and graphs, the values ​​of different magnitudes:
Position-time of one or several particles at a time
Speed-time
Acceleration-time
The most important thing that allows to check the validity of Physical Laws, using only a video that every student can make with their cell phone.