- James Prescott Joule -
- Born: 1818 Died 1889 -
Joule's career in the sciences began quite early in his life. As early as 16, Prescott was under the tutelage of James Dalton. His experiments soon followed in a laboratory he built in his family's basement. By this time, many scientists had begun hypothesizing on the interrelationships between heat, electricity, and magnetism - and by the 1840's Joule had formulated not only the well known "Joule's Law" but also a principle for conservation of energy. In the 1850's, Joule worked together with another scientist to come up with the "Joule-Thomson effect".
Possibly his most well-known experiment is his "Paddle wheel" experiment, which led to an understanding of the conversion of energy from one form to another.
His experimentations were not limited to simply those bounded in the areas of physics. Joule was an inventor as well - his accomplishments included the "arc" welding process and a displacement pump.
As with every scientist, there is a list of Joule's failures. He attempted to design a motor that would provide infinite power but after many failed attempts realized it was unobtainable.
- Joule's Law -
- 1840 -
Simply stated, Joule's Law relates how heat is dissipated by a resistor. Joule's Law states that the heat given off is equal to the square of the current multiplied by the resistance of the resistor and the amount of time passed.
This law also relates itself to Thermodynamics, stating that "at constant temperature the internal energy of an ideal gas is independent of volume."1
- Paddle Wheel Experiment -
- 1849 -
This experiment involved the dropping of weights from a specific height; these weights would churn the water inside of the bucket and increase the overall temperature of the water slightly. This relationship served as the foundation to the First Law of Thermodynamics:
- Joule-Thomson Effect -
Although relatively easy to grasp for anyone in Physics, this discovery was key in understanding the relationships between pressure of gas and its temperature. The Joule-Thomson Effect shows that an insulated gas will lower its temperature as the pressure is decreased without doing any work.
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
1) A stationary body will stay stationary unless an external force is applied to it; 2) Force is equal to mass times acceleration, and a change in motion is proportional to the force applied; and 3) For every action, there is an equal and opposite reaction. (Bio.org, 2017) He invented the optics which he helped to inspire the build of the
After graduating from MIT, he went straight into work at Bell Laboratory. He did most of his research in solid state physics, especially vacuum tubes. Most of his theoretical advances led the company to conquer their goal of using electronic switches for telephone exchanges instead of the mechanical switches there were using at the time. Some of the other research he did was on energy bands in solids, order and disorder in alloys, self-diffusion of copper, experiments on photoelectrons in silver chloride, experiment and theory on ferromagnetic domains, and different topics in transistor physics. He also did operations research on individual productivity and the statistics of salary in research laboratories.
Our most basic knowledge of chemical equilibria comes from a French man named Henry-Louis Le Chatelier. Through his studies of equlibria and the effects of changes provoked on these equilibria, he was able to come up with a principle that is studied widely today. Le Chatelier’s Principle, which was named after him, states that a change in one of the variables in a system at equilibrium will cause a shift in the position of the equilibrium that counteracts this system. Le Chatelier’s Principle is aimed at three changes that can cause a disruption in a system at equilibrium. These three changes include a change in the temperature of a reaction, a change in the concentration of one of the variable of a reaction, and a change in the pressure on a system. [1]
Although Black’s discovery of carbon dioxide was said to lay the foundation for modern chemistry, it wasn’t the only discovery he is credited for. He was the first to conclude that heat and temperature were two different things. Black used water as a universal substance to show that heat is energy, in which may be transported through moving and colliding molecules and the idea that temperature is the measurement of the average motion or kinetic energy of the molecules. He demonstrated this with a bucket of ice monitored by temperature constantly. The ice continually melted, but the temperature remained constant. Black is also well known for his discovery of latent heat, the heat required to convert a solid into a liquid or vapor, or a liquid into a vapor, without change of temperature. Latent heat was con be expressed in two ways: the heat can be absorbed if the change involves solid to liquid or liquid to gas or the heat can be released if the change involves gas to liquid or liquid to solid. Black took this idea and developed “specific heat”, in which is defined as the measured amount of heat required to raise the temperature of a substance by a specified number of degrees.
Franklin worked on his first electrical experiment in 1747 and was immediately intrigued. He continued with his electrical experiments including electrifying his kite string in a storm. He also examined how the storms worked. Franklin learned about how "air ways" cause different weather and storms.
This law, known as Gay-Lussac’s law, observes the relationship between the pressure and temperature of a gas. Contrary to its name, this relationship was actually discovered by French scientific instrument inventor and physicist Guillaume Amontons, and is occasionally referred to Amontons’ Law of Pressure-Temperature. While Guy-Lussac did explore the temperature-pressure relationship, Guy-Lussac’s law is usually used to refer to the law of combining volumes. Amontons stubble across this relationship when he was building an “air thermometer.” Although not many have been able identify his exact method of experimentation, later scientist developed an apparatus in which consisted of pressure gauge and a metal sphere. These two pieces were then attached and submerged in solutions of varying temperatures. From Amontons’ and Guy-Lussac’s research and experimentation, they determined that pressure and volume had direct relationship; as one increased, the other increased. The quotient of pressure and temperature was then found to equal a constant, in which just like Boyle’s law, could be used to find one of the two variables at another pressure or temperature, given one of the variables and that the other conditions remain the same. Instead of using various solutions at different temperatures like in the experiment describe above, many experiments today utilize a solution in which the temperature is increased or decrease, such as in the following
Benjamin Franklin is known for conducting lots of experiments dealing with electricity. His most famous being the kite experiment. He became fascinated with electricity when he was accidentally shocked in 1746. Benjamin wondered if there was a way to protect buildings and the people inside of them from lightning. He thought that this could benefit people in the colonies.
Background Knowledge -------------------- Pressure The three scientists Boyle, Amontons and Charles investigated the relationship between gas, volume and temperature. Boyle discovered that for a fixed mass of gas at constant temperature, the pressure is inversely proportional to its volume.
The first law of thermodynamics simply states that heat is a form of energy and heat energy cannot be created nor destroyed. In this lab we were measuring the change in temperature and how it affected the enthalpy of the reaction.
Thermodynamics is the branch of science concerned with the nature of heat and its conversion to any form of energy. In thermodynamics, both the thermodynamic system and its environment are considered. A thermodynamic system, in general, is defined by its volume, pressure, temperature, and chemical make-up. In general, the environment will contain heat sources with unlimited heat capacity allowing it to give and receive heat without changing its temperature. Whenever the conditions change, the thermodynamic system will respond by changing its state; the temperature, volume, pressure, or chemical make-up will adjust accordingly in order to reach its original state of equilibrium. There are three laws of thermodynamics in which the changing system can follow in order to return to equilibrium.
Henry Cavendish was born October 10, 1731 in Nice, France. His mother, Lady Anne Grey was the daughter of the first Duke of Kent while his father Lord Charles Cavendish, was second Duke of Devonshire. His ancestry links back to many of the aristocratic families in Great Britain. The chemist/physicist is most accredited for the discovery of hydrogen, the “inflammable air” and measuring the Earth’s density, but he also researched and discovered many other important scientific revolutions.
Throughout Thomson’s life he made many contributions to science. These include discoveries in thermodynamics and the age of the Earth, as well as innovating the Transatlantic Cable and inventing a tide meter. After exploring thermodynamics for some time, he developed the second law of thermodynamics. This law states that there cannot be a reaction that is completely efficient; a portion of the energy is lost to heat in each reaction. It also says that heat flows to areas that...
Boyle's law states that the volume of gas varies indefinitely with the pressure applied to it.
Conduction is a mode of heat transfer where heat energy is transported from more energetic particles to less energetic particles. The basic equation that describes heat transfer through conduction is Fourier’s law, as shown below.