The average acceleration of a body under a constant force can be determined using Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically, it can be expressed as:
a = F/m
where "a" represents the average acceleration, "F" represents the net force applied to the body, and "m" represents the mass of the body.
In this case, since the force is assumed to be constant, the average acceleration of the body will be constant as well as long as the mass remains constant.