The question as it appears in the 11/20 edition of Specs & Techs from GlobalSpec:
You are the operator of an elevator that when moving up or down, accelerates at 80% of gravity. Inside the elevator there is a pendulum clock you use to keep track of the time  you do not want to work more than eight hours per day. At the end of the day, do you work eight hours, more or less? By what percentage? Assume the time of accelerating up and down is the same.
(Update: Nov 27, 8:56 AM EST) And the Answer is...
The time interval, as recorded by the pendulum clock, is proportional to the frequency of the pendulum. This frequency is proportional to the square root of the effective gravitational field strength in the elevator. Let be the elevator's acceleration, where and is the acceleration of the Earth.
The effective gravitational field in the elevator is given by the following equations:
, when the elevator accelerates upward, and
, when the elevator moves downward.
Let and be the up and down times respectively, as measured by the pendulum clock, and let be the up and down time when measured by a resting clock. Then the total acceleration time of the elevator is as measured by a resting clock. As we saw above, these times are proportional to their respective gravitational field strength.
Now, let's calculate the ratio of the total accelerating time as measured by the pendulum to the true time measured by the resting clock.
For we get . Therefore, you end up working more than 8 hours a day. Exactly you work 10.56% more, or 50.69 minutes more.

Comments rated to be "almost" Good Answers: