Early life Chaplygin was born to Aleksei Timofeevich Chaplygin, a shop assistant, and Anna Petrovna in Ranenburg (present day
Chaplygin), Russia. After his father died when he was 2 years old, his mother remarried a tradesman and they moved to
Voronezh. There, he attended the Voronezh Gymnasium, which he graduated in 1886. After graduating from the university, he went on to become a professor there. In 1897, he published
On the motion of a heavy body of revolution in a horizontal plane, which was the first to present the general equation of motion of a
nonholonomic system. This equation is a generalisation of
Lagrange's equation. In 1899, he was awarded the Gold Medal of the
St. Petersburg Academy of Sciences.
Death Chaplygin died of a
brain haemorrhage in October 1942. ==Honours and awards==