Work done is equal to the force times the distance over which that force acts (provided they are parallel vectors) In symbols we say:
[tex] W= \int\limits^b_a { F^{.} } \, dr [/tex]
Since gravity acts downward and the elevator goes upward, the dot product is reduced to a simple multiplication problem. First we need the downward force of the elevator, which is the weight according to F=ma. F=1500kg*9.81m/s^2=14715N. Then W=14715N*100m=1471500J, or 1.4715MJ
