A simple, low-cost, data-logging pendulum built from a computer mouse

Lessons and homework problems involving a pendulum are often a big part of introductory physics classes and laboratory courses from high school to undergraduate levels. Although laboratory equipment for pendulum experiments is commercially available, it is often expensive and may not be affordable for teachers on fixed budgets, particularly in developing countries. We present a low-cost, easy-to-build rotary sensor pendulum using the existing hardware in a ball-type computer mouse. We demonstrate how this apparatus may be used to measure both the frequency and coefficient of damping of a simple physical pendulum. This easily constructed laboratory equipment makes it possible for all students to have hands-on experience with one of the most important simple physical systems.Comment: 3 pages, 3 figure

Unobserved individual and firm heterogeneity in wage and tenure functions: evidence from German linked employer-employee data

We estimate wage and job tenure functions that include individual and firm effects capturing time-invariant unobserved worker and firm heterogeneity using German linked employer-employee data (LIAB data set). We find that both types of heterogeneity are correlated to the observed characteristics and that it is therefore warranted to include individual and firm fixed effects in both the wage and the job tenure equation. We look into the correlation of the unobserved heterogeneity components with each other. We find that high-wage workers tend to be low-tenure workers, i.e. higher unobserved ability seems to be associated with higher job mobility. At firm level, there seems to be a trade-off between wages and job stability: High-wage firms tend to be low-tenure firms, which suggests that low job stability may be compensated by higher wages. High-wage workers seem to sort into low-wage/high-tenure firms. They seem to forgo some of their earnings potential in favour of higher job stability

The Effects of Social Media on the Women of Generation Z

This paper provides a thorough examination of the multifaceted influence of social media on the lives of young women from Generation Z. It begins by contextualizing social media as a pervasive force in contemporary society, defining its various functions and highlighting generational differences in usage. Through a balanced exploration of both positive and negative effects, the paper elucidates the complex relationship between social media and the development of young women. Positive aspects include increased connectivity, heightened awareness of social issues, and greater access to information. However, the paper also delves into negative consequences such as the pressure to maintain a curated online image and the heightened risk of online harassment and cyberbullying. Drawing on personal experiences and societal observations, the paper discusses how social media shapes self-perception, influences societal norms, and impacts mental health among young women. The paper examines the role of social media in activism and advocacy, illustrating how it empowers young women to raise awareness and connect with like-minded individuals. Despite the challenges posed by misinformation and online harassment, social media serves as a platform for young women to express themselves and drive positive social change. The paper emphasizes the importance of understanding the nuanced effects of social media on Generation Z women and calls for efforts to create a safer and more inclusive online environment. It underscores the potential for social media to empower young women while advocating for proactive measures to address its negative impacts

Identification with the need to achieve

How an ad featured in Seventeen magazine appeals to the need to achieve

Model B4 : multi-decade creep and shrinkage prediction of traditional and modern concretes

To improve the sustainability of concrete infrastructure, engineers face the challenge of incorporating new concrete materials while pushing the expected design life beyond 100 years. The time-dependent creep and shrinkage response of concrete governs the serviceability and durability in this multi-decade time frame. It has been shown that current prediction equations for creep and shrinkage underestimate material deformations observed in structures outside of a laboratory environment. A new prediction model for creep and shrinkage is presented that can overcome some of the shortcomings of the current equations. The model represents an extension and systematic recalibration of model B3, a 1995 RILEM Recommendation, which derives its functional form from the phenomena of diffusion, chemical hydration, moisture sorption, and the evolution of micro-stresses in the cement structure. The model is calibrated through a joint optimization of a new enlarged laboratory test database and a new database of bridge deflection records to overcome the bias towards short-term behavior. A framework for considering effects of aggregates, admixtures, additives, and higher temperatures is also incorporated