Work Definition in Chemistry

Work Definition in Chemistry The word work means different things in different contexts. In science, it is a thermodynamic concept.  The SI unit for work is the  joule. Physicists and chemists, in particular, view work in relation to energy: Work Definition Work is the energy required to move an object against a force. In fact, one definition of energy is the capacity to do work. There are many different kinds of work. Examples include: Electrical workWork against gravityWork against a magnetic fieldMechanical work Key Takeaways: Work Definition in Science In physical science, such as physics and chemistry, work is force multiplied by distance.Work occurs if there is movement in the direction of the force.The SI unit of work is the joule (J). This is the work expended by a force of one newton (N) over a displacement of one meter (m). Mechanical Work Mechanical work is the type of work most commonly dealt with in physics and chemistry. It includes work moving against gravity (e.g., up an elevator) or any opposing force. Work is equal to the force times the distance the object moves: w F*d where w is work, F is the opposing force, and d is the distance This equation may also be written as: w m*a*d where a is the acceleration PV Work Another common type of work is pressure-volume work. This is work done by frictionless pistons and ideal gases. The equation to calculate the expansion or compression of a gas is: w -PΔV where w is work, P is pressure, and ΔV is the change in volume Sign Convention for Work Note that equations for work employ the following sign convention: Work performed by the system on the surroundings has a negative sign.Heat flow from the system into the surroundings has a negative sign.

George Carruthers and the Spectrograph

George Carruthers and the Spectrograph George Carruthers has gained international recognition for his work which focuses on ultraviolet observations of the earths upper atmosphere and of astronomical phenomena. Ultraviolet light is the electromagnetic radiation between visible light and x-rays. George Carruthers first major contribution to science was to lead the team that invented the far ultraviolet camera spectrograph. What Is a Spectrograph? Spectrographs are images which use a prism (or a diffraction grating) to show the spectrum of light produced by an element or elements. George Carruthers found the proof of molecular hydrogen in interstellar space by using a spectrograph. He developed the first moon-based space observatory, an ultraviolet camera (see photo) that was carried to the moon by Apollo 16 astronauts in 1972*. The camera was positioned on the moons surface and allowed researchers to examine the Earths atmosphere for concentrations of pollutants. Dr. George Carruthers received a patent for his invention the Image Converter for Detecting Electromagnetic Radiation especially in Short Wave Lengths on November 11, 1969 George Carruthers Work With NASA He has been the principal investigator for numerous NASA and DoD sponsored space instruments including a 1986 rocket instrument that obtained an ultraviolet image of Comet Halley. His most recent on the Air Force ARGOS mission captured an image of a Leonid shower meteor entering the earths atmosphere, the first time a meteor has been imaged in the far ultraviolet from a space-borne camera. George Carruthers Biography George Carruthers was born in Cincinnati Ohio on October 1, 1939, and grew up in South Side, Chicago. At the age of ten, he built a telescope, however, he did not do well in school studying math and physics but still went on to win three science fair awards. Dr. Carruthers graduated from Englewood High School in Chicago. He attended the University of Illinois in Urbana-Champaign, where he received a bachelor of science degree in aeronautical engineering in 1961. Dr. Carruthers also obtained his graduate education at the University of Illinois, completing a masters degree in nuclear engineering in 1962 and a doctorate in aeronautical and astronautical engineering in 1964. Black Engineer of the Year In 1993, Dr. Carruthers was one of the first 100 recipients of the Black Engineer of the Year award honored by US Black Engineer He has also worked with NRLs Community Outreach Program and several outside education and community outreach organizations in support of educational activities in science at Ballou High School and other DC area schools. *Description of Photos This experiment constituted the first planetary-based astronomy observatory and consisted of a tripod-mounted, 3-in electronographic Schmidt camera with a cesium iodide cathode and film cartridge. Spectroscopic data were provided in the 300- to 1350-A range (30-A resolution), and imagery data were provided in two passbands (1050 to 1260 A and 1200 to 1550 A). Difference techniques allowed Lyman-alpha (1216-A) radiation to be identified. The astronauts deployed the camera in the shadow of the LM and then pointed it toward objects of interest. Specific planned targets were the geocorona, the earths atmosphere, the solar wind, various nebulae, the Milky Way, galactic clusters and other galactic objects, intergalactic hydrogen, solar bow cloud, the lunar atmosphere, and lunar volcanic gasses (if any). At the end of the mission, the film was removed from the camera and returned to earth.George Carruthers principal investigator for the Lunar Surface Ultraviolet Camera, discusses the instru ment with Apollo 16 Commander John Young, right. Carruthers is employed by the Naval Research Lab in Washington, D.C. From left are Lunar Module Pilot Charles Duke and Rocco Petrone, Apollo Program Director. This photograph was taken during an Apollo lunar surface experiments review in the Manned Spacecraft Operations Building at the Kennedy Space Center.