You have been asked to design a desk to use for a laptop. What factors should you determine so that you can decide on the maximum load the desk can support'?

answer; i do believe that the correct answer is : a deadly factory fire;

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.