(Solved): Two equal mass blocks are initially at rest and sitting on a frictionless surface. A hand exerts a ...

Two equal mass blocks are initially at rest and sitting on a frictionless surface. A hand exerts a force of magnitude $F$ on block A, which pushes it to the right by a distance $d$. Another hand exerts of force of the same magnitude $F$ on block B, which pushes it to the left the same distance $d$. A. Is the sign of the work $W_A$ the hand on the left does on block A positive, negative, or is it zero? Explain B. Is the sign of the work $W_B$ the hand on the right does on block B positive, negative, or is it zero? Explain. C. Consider the blocks $\mathrm{A}$ and $\mathrm{B}$ as the system. Is the sign of the net external work $W_{ext}$ done by the hands on the system positive, negative, or is it zero? Explain.