Newton's Second Law of Motion is expressed as F = ma. A lawn mower is pushed over a length of grass. If the pushing force suddenly doubles what will happen to the lawn mower's rate of acceleration? The mass of the lawn mower is constant. A. The acceleration will double. B. The acceleration will decrease by half. C. The acceleration will remain constant. D. The acceleration will triple.

From the given equation F = ma, which is Newton's Second Law of Motion (Law of Acceleration), it shows that force F is directly proportional to acceleration a. If it said that the pushing force F suddenly doubles, and the mass of the mower stays the same, then the only variable in the equation is the acceleration. Since they are directly proportional, we can conclude that the acceleration has also doubled. Among the choices, the correct answer is A.