Okay, here are the steps to solve this problem:
We are given an acceleration of the elevator of 2 m/s2
The acceleration is due to a net force being applied to the elevator
According to Newton's Second Law: Net Force = Mass x Acceleration
Or: Fnet = ma
We are given the net force applied is 2000 N
And the acceleration is 2 m/s2
So we can plug this into the equation:
Fnet = ma
2000 N = m x 2 m/s2
2000 N / 2 m/s2 = m
Solving this: m = 1000 kg
Therefore, the mass of the elevator that has a 2000 N force applied to accelerate it at 2 m/s2 is 1000 kg.