If you knew the power rating of the elevator's lift motor, how could you use this to determine the input energy? ?

power is energy per unit time, or energy is power x time.

so if you have a 1000 watt motor and it runs for 100 second, that is 100000 Joules of energy. 

Sorry, my answer is "Anonymous" as your post is Anonymous. There is no need for an Anonymous question in this category, Most 'Anonymous' posts are trolls, maybe yours is not, but the high likelihood is there. If you post as yourself, I would be glad to help you with any problem you have.
I spend a lot of time on each problem, I just want to make sure it's for a worthwhile cause.