Followups:
Mar. 8th, 2008 03:00 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
capri0mniSo, since the headache with having to verify my age, I went back and changed my journal settings to "No adult content," just a little while ago.
...And I'm still having to verify my age as over 14...
The cynical part of me want to say it's so I can be forced to see an ad every time I want to read my own journal... Even though I have a paid account, and even though it's my own name on the credit card (which should be proof enough that I'm an adult).
Meanwhile, a weather update: as I'm typing this, the wind has picked up, and the sky has darkened. Earlier this morning, there were more tornado watch alerts issued by the National Weather Service out of Wakefield, Virginia for cities west of here.
[ETA: Okay, the sky has cleared, since I started composing this post, but the wind is still cracking his cheeks with a fury.]
Here is the G.I.P. I threatened in my third-grade science post, from last night; it will probably show up on occasional skiency posts, and I may also use it to illustrate posts about wheelchair accessibility, 'cause, Dudes, where would I be without the combination of the Wheel and the Inclined Plane?
Also,![[livejournal.com profile]](https://www.dreamwidth.org/img/external/lj-userinfo.gif)
indefatigable42 and I got to talking via IM, last night, about whether or not the snowshoe counts as a seventh simple machine or not. As I was trying to drift off to sleep, this morning, I remembered a bit from the episode about the Inclined Plane, where they proved that the ramp is a machine by first hanging a toy car, vertically, from a spring scale, and showing the force exerted was (iirc) 2 lbs. Then, they pulled the toy car up the ramp by the same scale, and the force went down to one pound, or some such.
Surely, a similiar experiment could be set up for a snowshoe-like thing, with a toy car (or wooden block of some weight), a sandbox, and a piece of sturdyish cardboard (a stand-in for the snowshoe) that could be attached to hook of a spring scale.
Now, if you try to pull the car across the sand without the snowshoe, the scale will definitely show a greater force pulling against it than if you used the snowshoe tool. But I suppose it could only really be considered a "machine" if the force on the scale was less than the car hanging straight down...
In any case, the snowshoe works on the same basic principle as the ramp and the pully: it reduces the force (weight) exerted by an object by increasing the area over which that force is distributed, just as a ramp reduces the force needed to lift something up by increasing the distance across something has to travel... Oh, and btw, according to the ADA, in areas where there is little ice to deal with, the proper ratio of a wheelchair ramp should be at least one foot of horizontal lenth to one inch in height. Just sayin'; the ramp in my icon is not up to code...
I don't have access to a sandbox. Any skienzy types on my f'list want to try this for me?
[ETA: Okay, it looks like something is up with my cookie, because the icon that goes with this picture has gone back to default, instead of my GIP... and I did not do that... But what I did do, I just now remembered, is change the keyword for it from "Wheel+inclinedplane" to "Love machine," to be funny. Has LJ somehow decided that I am actually 13 years old, despite all evidence to the contrary? WTF? I mean, I wouldn't mind, so much, if I could have those thirty-one years of my life back, but I don't think that's happening...]
...And I'm still having to verify my age as over 14...
The cynical part of me want to say it's so I can be forced to see an ad every time I want to read my own journal... Even though I have a paid account, and even though it's my own name on the credit card (which should be proof enough that I'm an adult).
Meanwhile, a weather update: as I'm typing this, the wind has picked up, and the sky has darkened. Earlier this morning, there were more tornado watch alerts issued by the National Weather Service out of Wakefield, Virginia for cities west of here.
[ETA: Okay, the sky has cleared, since I started composing this post, but the wind is still cracking his cheeks with a fury.]
Here is the G.I.P. I threatened in my third-grade science post, from last night; it will probably show up on occasional skiency posts, and I may also use it to illustrate posts about wheelchair accessibility, 'cause, Dudes, where would I be without the combination of the Wheel and the Inclined Plane?
Also,
indefatigable42 and I got to talking via IM, last night, about whether or not the snowshoe counts as a seventh simple machine or not. As I was trying to drift off to sleep, this morning, I remembered a bit from the episode about the Inclined Plane, where they proved that the ramp is a machine by first hanging a toy car, vertically, from a spring scale, and showing the force exerted was (iirc) 2 lbs. Then, they pulled the toy car up the ramp by the same scale, and the force went down to one pound, or some such.Surely, a similiar experiment could be set up for a snowshoe-like thing, with a toy car (or wooden block of some weight), a sandbox, and a piece of sturdyish cardboard (a stand-in for the snowshoe) that could be attached to hook of a spring scale.
Now, if you try to pull the car across the sand without the snowshoe, the scale will definitely show a greater force pulling against it than if you used the snowshoe tool. But I suppose it could only really be considered a "machine" if the force on the scale was less than the car hanging straight down...
In any case, the snowshoe works on the same basic principle as the ramp and the pully: it reduces the force (weight) exerted by an object by increasing the area over which that force is distributed, just as a ramp reduces the force needed to lift something up by increasing the distance across something has to travel... Oh, and btw, according to the ADA, in areas where there is little ice to deal with, the proper ratio of a wheelchair ramp should be at least one foot of horizontal lenth to one inch in height. Just sayin'; the ramp in my icon is not up to code...
I don't have access to a sandbox. Any skienzy types on my f'list want to try this for me?
[ETA: Okay, it looks like something is up with my cookie, because the icon that goes with this picture has gone back to default, instead of my GIP... and I did not do that... But what I did do, I just now remembered, is change the keyword for it from "Wheel+inclinedplane" to "Love machine," to be funny. Has LJ somehow decided that I am actually 13 years old, despite all evidence to the contrary? WTF? I mean, I wouldn't mind, so much, if I could have those thirty-one years of my life back, but I don't think that's happening...]
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no subject
Date: 2008-03-08 11:50 pm (UTC)Snowshoes do spread out the force, but they don't change it overall. What changes is the pressure (which is defined as force/area) -- because the area is bigger with the snowshoe, the pressure is smaller for the same force. But it's not a machine, because it's not changing the direction or size of the force. I think.
And I'm really confused by the trouble you're having with the adult verification thing. I did wonder if you hadn't told LJ your birthday, but even I can see it on your profile so it's obivously not that ... It hasn't happened to me.
no subject
Date: 2008-03-09 12:43 am (UTC)no subject
Date: 2008-03-09 02:01 am (UTC)And yes, that Wikipedia article to which I linked says that a machine "requires the application of a single force to work," and you don't apply force directly to a snowshoe, per se. But you don't apply force to the ramp when you move things up or down it, either-- you apply it to the object you're moving up or down.
[edited to change the icon back... look to the ETA in the main post for even more weirdness]