Tuesday, June 12, 2007

Up, up with people...

Disclaimer: The reasoning and/or engineering skillz in this post are solely those of Queen Whackamole, and do not represent the fuller Fuller & Fuller skill set.

I'm generally a stair-taker, and have been for most of my life, rarely one to pass up the opportunity to burn a few extra calories. More stairs now = more beer later. Of course, there's the added benefit of saving energy by not using the elevator. So, several times each workday, I walk up four flights of stairs to my lair, burning calories, saving energy...

So, as I'm walking up the stairs, it occurs to me: what goes up, must come down. If it takes energy to take the elevator up, can it possibly require equal energy both directions? I don't think so.

It seems like it must take more energy for the elevator to lift a load than to drop it. And lifting a heavier load takes more energy than lifting a light load: Taking six people to the third floor is more work than taking one. So... here's the big question... is taking six people DOWN three floors LESS work than taking one? If I add my mass to the equation, is the elevator working less than it would without me?

What do you think? Obviously, I wouldn't want to call the elevator up to get me, but if it is already here... Is it better to go down in the elevator? (privacy concerns aside—speaking purely in terms of energy usage)

Which brings up the thought: Could elevators be designed like regenerative braking systems, so that the energy generated on the way down is stored for later trips up? Seems like. For all I know, they already are.

7 comments:

Marty said...

Elevators aren't designed that way, but could be and should be. And it is more work up than down, but, as you know from using those stairs, braking requires energy, but not as much, since you are working with gravity, and the excess kinetic energy could be stored in an elevator. And writing this paragraph reminds me why I got out of physics. (Sorry, Liz)

Queen Whackamole said...

I suspect this entry has reminded a lot of my teachers why I got out of physics too!

Well, less "got out" then was asked to leave...

George said...

I will not make a cheap going down in an elevator joke.

I will not make a cheap going down in an elevator joke.

I will not make a cheap going down in an elevator joke.

I will not make a cheap going down in an elevator joke.

MCConfrontation said...

I have absolutely no answer for your queries whackamole... but I feel compelled to divulge to you all my idea for the greatest invention ever: the reverse microwave. imagine a device that can make a warm beer cold in one minute. If I ever get a patent I can start a multimillion dollar empire and a huge buyout when they fire me (if George doesnt get his way).

Trekking Left said...

Doesn't it take more energy to walk down a hill than climb it, because you are restisting gravity? And wouldn't an elevator work the same way?

I guess Marty already addressed that. My head hurts.

MCConfrontation said...

I believe I have read something along the lines of what Lefty says, downhill takes more energy. It was right before my wife and I backpacked the Grand Canyon. I didn't believe people that said going down is harder than coming out, but you know what? They were right. While carrying out was exhausting and very aerobic, going down with full packs absolutely battered my knees and quads and back. Great trip, though.

amy said...

I would imaging that the elevator will take the same amount in either case. Both ways it is working against gravity. Unless of course you are on an elevator that free falls on the way down (a la tower of terror) then we're talking much savings on the way down! One because gravity does the work for you and two because you'll never ride that or any elevator again!