Final answer:
The work done by gravity on a 12.0 N block is 0 J, indicating that there was no vertical displacement of the block over which gravity could do work.
Step-by-step explanation:
The question pertains to the work done by gravity on a 12.0 N block. Work done by a force is defined as the product of the force applied and the displacement in the direction of the force. Since gravity is acting downwards, we consider the vertical displacement of the block to calculate the work done by gravity. If the block does not move vertically, or is on a horizontal surface with no change in elevation, the work done by gravity would be zero, as there is no displacement in the direction of the gravitational force.
According to the reference information given, the work done by gravity is Wgr = 0 J, indicating that the block has not changed position vertically or there was no vertical displacement over which gravity could do work.
This can be contrasted with examples where work by gravity would be non-zero, such as a block being lowered or raised vertically where the vertical displacement would be factored along with the gravitational force to determine the work done by gravity. In those cases, the formula used is W = mgh, where W is work, m is mass, g is the acceleration due to gravity, and h is the height change