Is the work W equal to 1/2mu^2 when the force is increasing in relation to time? For example, the acceleration of the mass at the end of the 1st sec is 1meter/sec^2, at the end of the 2nd sec is 2meters/sec^2, at the end of the 3rd sec is 3meters/sec^2 and so on. The initial velocity of the mass is zero, and u is the final velocity of the mass. The mass remains constant. (classical physics, not relativistic).