Indonesian Review of Physics

A Study of Tracker Software-assisted Spring Coupled Pendulum Oscillation

Ananda Aprilia — 2023-12-29

Oscillatory motions are an essential part of our physical world. These motions need to be studied and learned by students. However, complicated oscillatory motions, e.g.: spring coupled pendulum, are rarely taught to students because their analytical solutions (if they exist) are complicated Here, we use the Tracker software to bridge between the actual coupled pendulum oscillation and its analytical solution. This study aimed to determine the period and frequency of Tracker software-assisted spring coupled pendulum oscillations. The displacement of the pendulum is divided into in-phase and out-of-phase motions. Data collection was carried out by recording the oscillatory motions up to 10 oscillations. The data were obtained from the pendulum position with respect to time. The data analysis techniques in this study used two methods, namely: i) Tracker software and ii) analytical calculations. The results showed that the period and frequency obtained via the Tracker software were in accordance with the analytical calculations. The periods of the in-phase motion and analytical calculation were 1.42 s and 1.54 s, respectively. The periods of the out-of-phase motions and analytical calculation were 0.7 s and 0.55 s, respectively. The frequencies of the in-phase motion and analytical calculation were 0.70 Hz and 0.65 Hz, respectively. The frequencies of the out-of-phase motions and analytical calculation were 1.50 Hz and 1.83 Hz, respectively. The uncertainty values of the results were 7% to 22%. Hence, the spring coupled pendulum oscillations became tractable and can be compared to the analytical solution.

Students are Not Sure about Their Conceptual Understanding: A Comparative Study of the Level of Conceptual Understanding and the Level of Confidence Using Rasch Modeling

Toni Kus Indratno — 2023-12-29

Misconceiving fundamental physics concepts is a persistent challenge in education, hindering students' ability to grasp more advanced topics. This study aims to compare students' conceptual understanding and confidence levels using a 4-tier diagnostic instrument. Conducted as a survey involving 56 high school students in Yogyakarta, the research utilized a 4-tier diagnostic test covering topics of temperature and heat. Data were collected through Google Forms and analyzed using Excel and Winsteps 4.6.1 based on the Rasch Model. Data analysis involved coding, preparing raw data, and utilizing Wright maps combined with Logit Value of Person (LVP) for assessing students' conceptual understanding and confidence levels. Results indicated a significant inconsistency between students' conceptual understanding and their confidence, with many students displaying high confidence despite low understanding, and vice versa. This mismatch highlights the necessity for educational strategies that not only clarify concepts but also align students' confidence with their actual understanding. The study's implications suggest the need for more comprehensive diagnostic tools and targeted pedagogical interventions to enhance learning outcomes in physics education.

Flood Hazard Mapping in Bandung Regency Based on Multi-Criteria Decision Analysis (MCDA) with AHP Method

Riki Purnama Putra — 2023-12-29

Flooding is a natural disaster that can harm various parties, both harming nature and also harming humans. Floods can certainly hinder various human activities, both social and economic. Various causes of flooding can be caused by two main factors, namely natural factors and human factors. The natural factors in question are caused by nature, such as high-intensity rain, while the human factors are caused by humans, such as massive development and lack of drainage and humans' bad attitude towards the environment. This research aims to determine the probability of flooding in the Bandung Regency area. The research method used uses the Analytical Hierarchy Process (AHP) method based on Multi Criteria Decision Analysis (MCDA) using eight main factors, namely; (1) NDVI; (2) TWI; (3) Land Use; (4) Rainfall; (5) Slopes; (6) Elevation; (7) Distance from Road; and (8) Distance from River. Then the probability results are formed into a flood risk map for the Bandung Regency area with validation carried out using the ROC curve. The results obtained are that there are four risk categories, including; (1) Low Risk; (2) Quite Risk; (3) High Risk; and (4) Extreme Risk. The Bandung Regency area near Bandung City has the most High Risk to Extreme Risk, while outside that area has an average of Low Risk to Quite Risk. In addition, the validation results by comparing the obtained maps with the flood maps that occurred in 2002–2022 obtained an average ROC curve percentage of 76.4%, and these results show that the flood risk hazard map for Bandung Regency is valid.

The Effect of Percentage Variation of Ketapang Fruit Biobrickets on Health Value and Combustion Rate

Himmi Raudatul Fadilah — 2023-12-29

This study aims to determine the effect of variations in the percentage of Ketapang fruit (KF) bio briquette on calorific value and burning rate. This research is experimental in a physics laboratory with a literature review carried out in three stages, namely the preparation stage, the bio briquette manufacturing stage, and the bio briquette testing stage. The main ingredient used in the manufacture of bio briquettes is Ketapang fruit. The adhesive materials used were tapioca flour and sago flour with percentages of 10%, 12.5% and 15%. The results showed that the calorific value of the following bio briquettes using the tapioca predicate included 5,139.45 Cal, 5,540.97 Cal, 5,922.42 Cal, and those using the sago predicate including 2,409.12 Cal, 3,653.83 Cal, 3,894.74 cal. The highest calorific value was in bio briquettes with tapioca adhesive type in the sample at 85%:15%. The burning rate of bio briquettes using tapioca glue included 1.98 gr/minute, 1.76 gr/minute, 1.62 gr/minute and those using sago glue included 2.62 gr/minute, 2.50 gr/minute, 2.31 gr/minute. The lowest burning rate value was in bio briquettes with the type of sago glue in the sample at 85%:15%. Based on the test results, it is known that the lower the percentage of keta pang fruit in the bio briquettes, the lower the burning rate, and the resulting calorific value increases.

Assessing the Efficacy of the UV Index in Predicting Surface UV Radiation: A Comprehensive Analysis Using Statistical and Machine Learning Methods

Edy Ervianto — 2023-12-29

The study investigated the relationship between the UV Index and measurements of ultraviolet A (UVA) and ultraviolet B (UVB) radiation to evaluate the effectiveness of the UV Index in predicting and understanding UV radiation at the surface. The implications of this study are significant for public health policies and UV protection strategies. This study used a variety of statistical analyses and modelling techniques, including ANOVA, Naive Bayes classification, decision trees, artificial neural networks, support vector machines (SVM), and k-means clustering, to examine relationships and predict UV Index values. ANOVA analysis showed a significant relationship between the UV Index and UVA and UVB measurements. Prediction models such as Naive Bayes classification, decision trees, and artificial neural networks showed variability in their accuracy. Notably, SVM showed a high degree of accuracy in predicting UV Index values, while k-means clustering effectively clustered the data based on similarities in UV Index and UV measurements. These findings confirm that the UV Index is a reliable indicator for predicting and understanding UV radiation levels at the Earth's surface. This research underscores the importance of developing more accurate and precise UV Index prediction models. Further investigation is essential to understand the temporal variations and environmental impacts on the UV Index, as well as the broader implications of UV exposure on public health. This study lays a strong foundation for the development of early warning systems and more effective UV protection strategies, ultimately improving public health outcomes and safety measures against UV radiation.