Motion (physics) In physics, motion is a change in position of an object over time. Motion is described in terms of displacement, distance, velocity, acceleration, time and speed. Motion of a body is observed by attaching a frame of reference to an observer and measuring the change in position of the body relative to that frame.
ADHD, medication rates in U.S. continue to rise. Attention deficit hyperactivity disorder (ADHD) rates in the United States continue to rise, with 11 percent of children ages 4-17 having received a diagnosis in 2011, according to a study released Friday.
ADHD Overview. ADHD stands for attention deficit hyperactivity disorder, a condition with symptoms such as inattentiveness, impulsivity, and hyperactivity. The symptoms differ from person to person. ADHD was formerly called ADD, or attention deficit disorder. Both children and adults can have ADHD, but the symptoms always begin in childhood. Adults with ADHD may have trouble managing time, being organized, setting goals, and holding down a job.