Answer:
19.0 m/s
Step-by-step explanation:
First of all, we can find the acceleration of the object by using Newton's second law:

where
F = 200 N is the net force applied to the object
m = 50.0 kg is the mass of the object
a is the acceleration
Solving for a,

Now we can find the final speed of the object:

where
u = 3.0 m/s is the initial speed
a = 4.0 m/s^2 is the acceleration
t = 4.0 s is the time
Substituting,
