Answer:
a)
b)
Explanation:
Given the information from the exercise we can calculate the work done by the elevator using the following formula:
a) Considering you and your belongings as a system we know that the elevator is applying a Normal reaction force of:
Since the force applied and the displacement is in the same direction, the work done by the elevator is positive
b) The reaction force applied by the elevator is the same as the weight of the person
Since the force applied and the displacement is in opposite direction, the work done by the elevator is negative