a). F= m a
500 N = (m) (5.00 m/s^2)
m = 100 kg
b). Accelerating body covers distance of
D = 1/2 a T^2
D = 1/2 (5.00 m/s^2) (100 s)^2
D = 25,000 meters
Note: I'm pretty sure the acceleration is typed wrong in the question. If so, then these answers won't be correct.