Answer :

I'm assuming that the cart starts from rest.

Initial velocity (vi): 0 m/s
Final velocity (vf): ?
Acceleration (a): ?
Force (F): 200 N
Mass (m): 50 kg
Time (t): 10 s

F= ma
200 N= (50kg)(a)
a= +4 m/s^2

a= (vf-vi)/t
+4 m/s^2= (vf - 0m/s)/10s
vf= 40 m/s

Answer: the cart will be moving 40 m/s.
AL2006

Acceleration = (force) / (mass)

If there is no friction . . .

Acceleration = (200N) / (50 kg) = 4m/s²

Change in speed = (acceleration) x (time) = (4 m/s²) x (10 sec) = 40 m/s

Final speed = (speed of the cart before the force began) + (40 m/s more)

(That's about 89 mph faster than the cart was moving before the force started.)