Physics is taught in high schools, college and graduate schools. In the US, it has traditionally not been introduced until junior or senior year (i.e. 12th grade), and then only as an elective or optional science course, which the majority of American high school students have not taken. Recently in the past years, many students have been taking it their sophomore year.
Physics First is a popular and relatively new movement in American high schools. In schools with this curriculum 9th grade students take a course with introductory physics education. This is meant to enrich students understanding of physics, and allow for more detail to be taught in subsequent high school biology, and chemistry classes; it also aims to increase the number of students who go on to take 12th grade physics or AP Physics (both of which are generally electives in American high schools.) But many scientists and educators argue that freshmen do not have an adequate background in mathematics to be able to fully comprehend a complete physics curriculum, and that therefore quality of a physics education is lost. While physics requires knowledge of vectors and some basic trigonometry, many students in the Physics First program take the course in conjunction with Geometry. They suggest that instead students first take biology and chemistry which are less mathematics-intensive so that by the time they are in their junior year, students will be advanced enough in mathematics with either an Algebra 2 or pre-calculus education to be able to fully grasp the concepts presented in physics. Some argue this even further, saying that at least calculus should be a prerequisite for physics.