Answer:
Friction Opposes Motion of an Object.
Now
To get the Net force that Moves an Object and causes acceleration....You subtract the Frictional force
Net force = Pushing Force - Frictional Force
Recall
Net Force; F=Ma
Ma = P - Fr
Now the question asked for How Much force Must be applied to Maintain a Constant velocity.
In a Constant Velocity Motion... Acceleration do not change... Its Zero
So Putting this into the formula above
M(0) = P - Fr
0=P - Fr
Fr = P.
This means
That The force needed to keep this object Moving at Constant Velocity Must be equal to its Frictional Force
Since Frictional Force; Fr =223N
The Applied Force(Pushing Force) Must be equal to 223N too.