The United States of America (USA), commonly referred to as the United States (U.S.) or America, is a federal republic composed of 50 states, The United States is a developed country and has the world's largest national economy by nominal and real GDP, benefiting from an abundance of natural resources and high worker productivity. it ranks among the top 10 in the world in several measures of economic well-being, including average wage.
Canada and Mexico shares the land borders with The United States and Russia, Cuba shares maritime borders with the United States and the Bahamas in addition to Canada and Mexico. the total area of the US is 9,372,610 km2 includes land and inland water. The listed total area changed to 9,629,091 km2 in 1997 due to the addition of Great Lakes area and coastal waters, changed to 9,631,418 km2 in 2004, in 2006 it was 9,631,420 km2, in 2007 it was 9,826,630 km2 due to th addition of territorial waters. The United States is either slightly larger the People's Republic of China.
The United States is the world's largest national economy in nominal terms and in purchasing power parity (PPP) it is in the second largest position, representing 22% of nominal global GDP and 17% of gross world product (GWP). The United States' GDP was estimated to be $17.914 trillion as of Q2 2015 The U.S. dollar is the currency most used in international transactions and is the world's foremost reserve currency The US has abundant natural resources, a well-developed infrastructure, and high productivity.
357 Noble Laureates are there from this country and number of Physics Journals are published from US with good reputation. The major leading intitutions in US in the physics includes Harvard University, Stanford University, University of Wisconsin - Madison, Pennsylvania State University - University Park etc.. Current Research work in physics by Some Auburn scientists are in atomic and molecular collision physics, collision, free electron laser experiments, Audiology , Biophysics , Applied Physics , Biophysics , Cellular Physiology , physics of condensed matter, atomics, molecular physics and optics, high energy physics and astrophysics. quantifying gravity, Thermal conductivity