View source for United States Physics Olympics

The '''United States Physics Olympiad''', or '''USAPhO''', is comprised of 2 exams, the '''<math>\mathbf{F}_{\textbf{\text{net}}} = \mathbf{ma}</math> exam''', or screening exam, and the '''semi-final exam'''.  In 2008 and 2009, there was an additional '''quarter-final exam''' between the F=ma and semi-final. '''USAPhO''' is sometimes used to refer to just the semi-final exam, as it is the last of the national physics exams (and is thought of as analogous to [[USAMO]]).

==<math>\text{F}_{\text{net}} = \text{ma}</math> exam==
Any high school student in the US is eligible to take this exam.

The test is 75 minutes long, with a total of 25 possible points.  It is composed of 25 point multiple choice section each worth 1 point with a 1/4 point deduction for incorrect answers.

From the results of the preliminary exam, approximately the top 400 are chosen to participate in the United States Physics Olympiad Semifinal exam. 

== Semi-final Exam ==
Approximately the top 400 scorers on the preliminary exam are invited to take the semi-final exam.  The purpose of this exam is to select the members of the US Physics Team.

The Semi exam is a 2 part, 3 hour exam, with a total of 200 possible points, and is entirely composed of free response problems.  Part A is 90 minutes long and contains 4 problems, worth 25 points each that can cover any topic in physics. Part B is also 90 minutes in length and contains 2 problems, worth 50 points each.  These problems are longer and generally more difficult than those in part A, and can cover any topic.

The tests are the primary measure used to select the 20 members of the US Physics Team.  Once selected, the top 20 students are invited to attend a training camp in May or June, from which the top 5 students and 1 alternate are selected to compete in the '''International Physics Olympiad,''' or '''IPhO''' as the US traveling team.

== Sample Problems ==
Although the difficulty varies from year to year, both the F_net=ma and the semi-final exams from previous years can be found at [http://aapt.org/physicsteam/2014/exams.cfm].