The Friction Force that acts on a sliding bookcase is -120 N
<u>Explanation:</u>
Frictional force is the force developed by the two surfaces where they contact and slide against each other. They mainly affected by amount of force impelled them together and by the angle and position of the object.
Frictional Force F = Coefficient of friction * normal force
At a constant velocity, there will be no acceleration and the net force will be zero.
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