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Explanation:
Let's say you want to push the brick to the right. The free body diagram will have an arrow pointing right on the rectangle (the brick) and the arrow is labeled with 35 N.
Friction always counteracts whatever force you apply. The friction force arrow will point left and be labeled with 7 N.
The net horizontal force is therefore 35-7 = 28 N and the direction is to the right. The positive net force means you've overcome the force of friction and the brick is moving.
F = 28 is the net force
m = 6 is the mass
a = unknown acceleration
F = m*a .... newton's second law
28 = 6a
6a = 28
a = 28/6
a = 4.67
The acceleration of the brick is approximately 4.67 m/s^2
This means that for every second, the brick's velocity is increasing by about 4.67 m/s.