Two forces act on a 5 kg object: F1 = 60N applied at the origin in the direction of the positive x-axis, and F2 = 40N, also applied at the origin but in the direction of the positive y-axis. Calculate the magnitude of the object's acceleration.
a. 14.4 m/s^2
b. 45.1 m/s^2
c. 72.1 m/s^2
d. 20.0 m/s^2