While working out with weights recently, I remembered hearing back in high school(a few decades ago),that lifting
a 150 lb person was more difficult than lifting 150 lbs of
weights, because of the difference between live weight and dead weight. It this true, or is it just more difficult to lift a person because they don’t come with bars or handles?
“live weight” will actively balance itself and shift its center of gravity to the most stable position. This makes it easier to lift as it maximizes your leverage. “Dead weight” doesn’t do anything. Energy is frequently wasted just getting a proper hold of the thing and maintaining your leverage and balance
Welcome to the boards. This was one of the first questions I ever posted, and I’d post the thread, except that it’s hard to retrieve stuff from that far back.
But, as as already been answered, “dead weight” is better described as “unstable center of mass.” One of the examples in the (my) old thread was a mattress. A mattress of a certain weight is harder to manage that a piece of furniture of the same weight because of the instability.
Same with a limp person, and a person who is rigid. (Wonder if that ties in to the old parlor trick of lifting a person with just the fingers, somehow. . . .)
I don’t know. When I try to carry a ‘live’ woman she is always kicking and biteing and screaming for the cops. Much easier to carry dead weight if you know what I mean.
[sub]The proceeding was a joke. It was only a joke.
I wonder if a dead body is even more unstable than, say, a flexible dummy of the same weight because the circulatory system is shut down. Blood starts squishing around and stuff…
Just a thought.
Submitted for your perusal. . .
http://boards.straightdope.com/sdmb/showthread.php?threadid=4939
So in Faraway, So Close!, when Emit Flesti tells Cassiel to “Make yourself dead weight - humans are heavy” so that he’ll drop further on the bungee rope… is he talking mince or not? Or was that more a question of aerodynamics?
Appendix
If you haven’t seen the movie you’re going to have to find a copy anyway, because it’s terrific. Just read Emit Flesti’s name backwards for his true identity - that’s the kind of characters you have to deal with in this flick!
Ross – I always had the feeling the science wasn’t really backing him up on that line. However, it is of course meaningful in context. It’s a contrast with the earlier scenes (using the same equipment) in which Cassiel simulates flying – being an angel. Emit has to tell him to stop holding back when falling and act more like a human.
Faraway, So Close! (aka In Weiter Ferne, So Nah!) is in my favorite movie. And it’s finally out on DVD, with the scene on the motorcyle (which was inexplicably missing in the American theatrical release) restored (the VHS doesn’t have it).
Yes. In order to make my favorite movie, you actually have to combine other films together.
No, I really meant it is my favorite movie, no exceptions or additions.
Pro wrestlers I think give a good example of how much easier it is to move live weight. I’m not talking about the slap-the-guy-and-he-flies-over-the-top-rope thing where the victim jumps, but more when they pick each other up. Even those monsters would have difficulty lifting an unconsious 160lb drunk over their heads; although they can do the same to a 260lb wrestler who’s staying rigid and helping the lifter with the balance. Same might go for the guys/girls who do circus gymnastics where you get 3 people doing hand stands on one guy’s head. Just try to balance/maneuver 300lbs of dead weight and you’re likely to wake up in the hospital!!