*Problem 1: **A particle of mass m, originally at rest, is subjected to a force whose direction is constant but whose magnitude varies with the time according to the relation*

* *

*where F _{0} and T are constants. The force acts only for the time interval 2T.*

*Prove that the speed v of the particle after a time 2T has elapsed is equal to 4FoT/3 m.*

**Solution :**