We simply use the formula,

Given, velocity = 4 m per s and distance = 120 m.
Substituting these values, we get
.
Thus, required time for the elevator in order to travel 120 m upwards is 30 s.
The forces are Andrew poking the marble and then gravity pulling the marble downward
After they have gathered enough information by testing the theory.
Is there any other information given? I don't think you can solve this without a time