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ReverendTed Member Profile  Member Since: 2006-05-03 AIM: Tehd57 MSN: ted_57@hotmail.com Last Power Points used: 2009-09-10 • Available: now Max Power Points: 1 • Get More Power Points Now Comments 1 |
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Member Stats Rank: 530 Rating: 19 star points Top 15 Videos: 1 Votes Received: 359 Average Votes Per Video: 23.93 Votes Cast: 435 Comments Posted: 572 • browse Comments Applauded: 8 Sifted Videos: 15 Dead Pool Fixes: 4 Profile Views: 4411 Highest Ranked Comments |
Wtf Videos Submitted by ReverendTed
In reply to this comment by ReverendTed:
Has anyone else complained of pop-up ads on the Sift?
I got a Classmates ad and a couple of opinioncentral ads popping into new tabs - something that's only happening here.
In reply to this comment by ReverendTed:
Now I can know who my true friends are!
(Different topic, but what does the "clean" button above the comment entry box do?)
Edit: I shall keep your objurgation in mind in the future, Mister Fisk.
In reply to this comment by ReverendTed:
One interesting thing is that shot glass didn't actually produce the hit I was expecting; instead it hit the writer's offhand remark about a "shot of acquitted felons streaming out of the courthouse". But it worked, so hey.
It's Lazydude's fault he's hard to find, though. He wore the bathrobe to distinguish himself - he should have included that tag somewhere in his video descriptions.
In reply to this comment by MarineGunrock:
Haha. That's damn near the same string of keywords that I used! I just didn't scroll all the way down! Thanks!
In reply to this comment by ReverendTed:
I Googled movie reviews bathrobe shot glass and the last link on the first page was your answer: Lazydork.
In reply to this comment by ReverendTed:
I Googled movie reviews bathrobe shot glass and the last link on the first page was your answer: Lazydork.
Sadly, he's just not edgy enough for today's viewers.
That's such a painful pun I can't not upvote it. Well played.
a) The cart needs to be held on the treadmill because it is only a valid simulation for motion at 10mph (if the treadmill is going at 10mph). In real wind, the prop has shaped blades such that they act like a sail to bring the cart up to windspeed. In enough wind, the cart doesn't need any initial force. In the large cart video the wind is about 6mph and the cart is too heavy to be pushed by the wind, so it needs to be started VERY gently. If the wind was say 15mph, the cart would probably start on its own.
b) The cart has a terminal velocity based on the air resistance (drag) that it faces from travelling faster than the wind. If it travels 10mph faster than the wind, it faces 10mph worth of drag, and when the drag force exerts the same force as the prop (in the opposite direction), the cart will have reached terminal velocity.
c) If you introduced a 10mph tailwind to the 10mph treadmill scenario you are basically doubling the windspeed. Please read my latest post and hopefully you will see this and understand what i'm about to write. If you did this, the cart would go flying off the treadmill (assuming the cart behaves in a proportionate way at all windspeeds). If it landed on the floor on its wheels and in the right direction, and the windspeed of 10mph was still present, then the cart would behave as it did on the treadmill because now the wind is the only source of power.
In reply to this comment by ReverendTed:
It takes a minute to wrap your head around this one, but I think it makes sense.
I'm still fighting with the equivalence of the treadmill scenario, though. On the treadmill, the energy input is through the wheels and the output is through the propeller. Similar to the "push" the wife gave the original device, the test device would need to be held in place on the treadmill until the propeller got going, otherwise it would simply fall off the back of the treadmill. A 10-mph treadmill does not equal a 10-mph tailwind, since the treadmill guarantees 10-mph, while the tailwind only guarantees what air friction will impart to the device. (Which would be less than 10, right?)
Once it's going, it makes sense to me, though - the rotational energy from the wheels is converted into lift (directed horizontally) in the propellers. As long as there is energy being delivered to the wheels, the propeller will spin and provide more lift, which will *supplement* the forward motion of the wheels and cause the device to travel forward. I'm assuming the supplement is steady, though - that is to say it doesn't continue to accelerate, but reaches a steady "overspeed". (As opposed to a perpetual motion machine, which would continue to accelerate.)
What's helpful to me is to picture the device being allowed to run off the treadmill into dead air - it would propel itself somewhat using the residual "lift" from the propeller, but would eventually coast to a stop. Now, taking that image, if we introduce a tailwind, that could introduce enough energy to keep the device moving forward. Maybe? Hrm.
HRRRRRRRMMMM.
In reply to this comment by ReverendTed:
Drat. I am unable to call * notdead, though it is quite old.