# Alex is asked to move two boxes of books in contact with each other and resting on a rough floor. He decides to move them at the same time b

Question

Alex is asked to move two boxes of books in contact with each other and resting on a rough floor. He decides to move them at the same time by pushing on box A with a horizontal pushing force FP = 8.9 N. Here, A has a mass mA = 10.2 kg and B has a mass mB = 7.0 kg. The contact force between the two boxes is FC. The coefficient of kinetic friction between the boxes and the floor is 0.04. (Assume FP acts in the +x direction.)

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1 year 2021-09-03T14:53:15+00:00 1 Answers 68 views 0

Explanation:

The force of friction acting on the system

= .04 x 9.8 ( 10.2 + 7 )

= 6.74 N

Net force = 8.9 – 6.74

= 2.16 N

Acceleration in the system

= 2.16 /  ( 10.2 + 7 )

= .12558 m / s ²

Contact force between boxes = FP

Considering force on box A

Net force = 8.9 – FP

Applying Newton’s law on box A

8.9 – FP = 10.2 x .12558

= 1.28

FP = 8.9 – 1.28

= 7.62 N