A block of mass 'm' is lowered with the help of a rope of negligible mass through a distance 'd' with an acceleration of g3. Work done by the rope on the block is
Tension and acceleration due to gravity acts on the block. Such that
T−mg=ma
T=m(g−a)
T=m(g3−g)
=−2mg3
Work done = force×displacement
=−2mg3.d
=−2mgd3