Accelerate
In the strict scientific sense, to accelerate an object is to change its acceleration over a period of time. Note that also in the scientific sense, the definition of acceleration includes both positive and negative acceleration -- called acceleration and deceleration in common speech, respectively. Acceleration is defined technically as "the rate of change of velocity of an object with respect to time". It is given by the equation a = v/t , where a is the acceleration vector, v is the velocity vector expressed in m/s, and t is the elapsed time expressed in seconds. This equation gives a the units of m/s/s, or m/s2 (read properly as "meters per second per second", informally as "meters per second squared").