Answer:
200 N
Step-by-step explanation:
There is only two needed factors in play here; the mass and acceleration
According to Newton's 2nd Law: F = m*a
Now Acceleration is Velocity over Time, so we have another factor in play: Acceleration = 50-30/5 = 20/5 = 4m/s^2
Net force = (50 kg)(4 m/s^2) = 50*4 = 200 Newtons