The statics of fluids may seem simple at first but often poses problems for students when it comes to applying it to concrete cases. Despite its relatively simple laws, some subtleties, mainly related to the elastic characteristics of a fluid, must be noted. This elasticity allows the pressure exerted in a part of the fluid to propagate in its…

Although the old problem of rotating liquid is described and solved in many textbooks and articles, the story still remains interesting. Intuitive understanding of the equipotential spatial surfaces is very difficult. This article is an attempt to present Newton's rotating tank in the light of the law of conservation of energy.

The long and complex history to define the composition of water as H[subscript 2]O is summarized. This case study could be useful not only to introduce the history of chemistry in the classroom but also to teach the basic tenets of the nature of science (NOS). Water has been present in several turning points in the history of chemistry such as the…

One of the most popular demonstration experiments pertaining to Bernoulli's principle is the production of a water spray by using a vertical plastic straw immersed in a glass of water and a horizontal straw to blow air towards the top edge of the vertical one. A more general version of this phenomenon, appearing also in school physics problems, is…

We have observed a nice example of chromatic dispersion due to refraction in water, in the form of color fringes bordering the black stripes that exist at the bottom of a swimming pool. Here we give a qualitative description of the phenomenon, explaining the role of the black stripes and the dispersive index of refraction of water.

Next Generation Science Standards (NGSS), with new emphasis on engineering, reflects broadening definitions of scientific and technological literacy. However, engaging in science and engineering practices is necessary, but insufficient, for developing technological literacy. Just as robust scientific literacy includes a deep understanding of the…

Previously appearing in this journal were photographs of a physics apparatus, developed circa 1880, that was believed to be used to demonstrate the "Bernoulli effect." Drawings of these photographs appear here and show that when there is no flow, the water level h[subscript PT2] in the piezometer tube at location (2) is at the same level…

A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

One tried-and-true way to hook students' attention and promote long-lasting understanding is to sequence science instruction in an explore-before-explain instructional sequence. In these lessons for the second through sixth grade band, elementary students investigate the interaction between "cold" and "hot" substances and…

The hydraulic impulse pump utilizes a fraction of the momentum of a flowing stream to lift a small portion of that water to a higher level. There it may be accumulated in an elevated cistern to provide sufficient water for several families, for the pump works 24 h a day with no additional source of energy. The operation of the pump is described,…

This paper begins with an early measurement of the speed of sound in water. A historical overview of the consequent development of SONAR and medical imaging is given. A method of measuring the speed suitable for demonstration to year 10 students is described in detail, and an explanation of its systematic error examined.

In nature, water drops can have a large variety of sizes and shapes. Small droplets with diameters of the order of 5 to 10 µm are present in fog and clouds. This is not sufficiently large for gravity to dominate their behavior. In contrast, raindrops typically have sizes of the order of 1 mm, with observed maximum sizes in nature of around 5 mm in…

This paper aims to clarify the misconception about the violation of the principle of floatation. Improper understanding of the definition of "displaced fluid" by a floating body leads to the misconception. With the help of simple experiments, this article shows that there is no violation of the principle of floatation.

This article describes an alternative method to determine the refractive index of transparent liquids. The method only requires a laser pointer, a ruler and a modified fish tank.