Two Boxes, a and B, Are Connected by a Horizontal

question 8

Multiple Choice

Two boxes, A and B, are connected by a horizontal string S on a horizontal floor. A very light wire pulls horizontally on box B, as shown in the figure, with a force of 100 N. The reaction force to this pull is

• A) the pull that box B exerts on string S.
• B) the pull that string S exerts on box B.
• C) the pull that string S exerts on box A.
• D) the pull of box B on the wire.
• E) the force that box A exerts on box B.