Practice Problems $($PHYS $2010)$

$12.$ An elevator car with a mass of equal to $800$ kg is pulled upward at constant speed. If the elevator moves a distance of $5$ m $,$ how much work was done by the cable which pulls upward on the elevator through that distance.

ditamete $5$

A$.$ The cable does no work, because there is no change in kinetic energy

B$.$ The cable does $40,000J$ of work, because it must be equal to gain in potential energy.

C$.$ The cable does more than $40,000J$ of work, because it must work harder than earth