Physics HELP!!
posted by Ann .
Two horizontal forces F1 and F2, are pulling an object of mass 3.05kg from two opposite sides. F1 pulls to the right and F2 pulls to the left. The magnitude of F1 is 99.2N. The object moves strictly along the horizontal xaxis, which we chose as positive to the right. Find the magnitude of F2 if the object's horizontal acceleration is 7.21m/s^2.
b). Find the magnitude of F2 if the acceleration is 0m/s^2.
c).Find the magnitude of F2 if the acceleration is 7.21m/s^2.

(a) ma=F1F2
F2=F1ma
(b)F2=F1
(c) ma=F1F2
F2=F1+ma 
Matatatamag