We discuss the limits of the equation of the period of a simple pendulum, T[subscript s] = 2[pi][square root]l/g, frequently used in high-school and university classrooms to measure the acceleration of gravity. We evaluate the relative error in determining the acceleration of gravity with this simple equation instead of a more realistic one,…

When a shock wave interacts with a contact discontinuity, there may appear a reflected rarefaction wave, a deflected contact discontinuity and a refracted supersonic shock. The numerical simulation of shock wave refraction at a plane contact discontinuity separating gases with different densities is performed. Euler equations describing inviscid…

An interesting problem in fluid mechanics, with significant educational importance, is the classic hydrostatic paradox. The hydrostatic paradox states the fact that in different shaped containers, with the same base area, which are filled with a liquid of the same height, the applied force by the liquid on the base of each container is exactly the…

The temperature dependence of the Gibbs energy and important quantities such as Henry's law constants, activity coefficients, and chemical equilibrium constants is usually calculated by using the Gibbs-Helmholtz equation. Although, this is a well-known approach and traditionally covered as part of any physical chemistry course, the required…

We compare the period of oscillation of an ideal simple pendulum with the period of a more "real" pendulum constituted of a rigid sphere and a rigid slender rod. We determine the relative error in the calculation of the local acceleration of gravity if the period of the ideal pendulum is used instead of the period of this real pendulum.

This research aims to produce a learning instrument based on hypermedia which is valid, interesting, practical, and effective as well as to know its influence on the problem based skill of students Mathematical and Science Faculty, Makassar State University. This research is a research and development at (R&D) type. The development procedure…

We describe a method for the accurate calculation of bound-state and resonance energies for one-dimensional potentials. We calculate the shape resonances for symmetric two-barrier potentials and compare them with those coming from the Siegert approximation, the complex scaling method and the box-stabilization method. A comparison of the…

Here, we present complex resonance states (or Siegert states) that describe the tunnelling decay of a trapped quantum particle from an intuitive point of view that naturally leads to the easily applicable Siegert approximation method. This can be used for analytical and numerical calculations of complex resonances of both the linear and nonlinear…

Multi-ball collisions inside the Astroblaster toy are explained from the conservation of momentum point of view. The important role of the coefficient of restitution is demonstrated in ideal and real cases. Real experimental results with the simple toy can be compared with a computer model represented by an interactive Java applet. (Contains 1…

In this experiment, physical science students measured the mass of several soda cans, measured the mass and volume of water displaced when these cans were placed in water, and determined whether these cans sank or floated in water. Then, the students plotted graphs of the mass of displaced water versus the volume of displaced water, the mass of…