Comments on: Egregious Waste In The Name Of…. well, I’m not quite sure http://regex.info/blog/2008-07-01/853 Not a photo blog, but sometimes I play one on TV Fri, 05 Dec 2008 16:23:40 +0000 http://wordpress.org/?v=2.0.12-alpha by: Andrew S http://regex.info/blog/2008-07-01/853#comment-18641 Sun, 06 Jul 2008 09:03:05 +0000 http://regex.info/blog/2008-07-01/853#comment-18641 Helicopter blade speeds are pretty easy to calculate! They need to stay under the speed of sound at the tips, else bad things happen. So, say they're limited to 1000 ft/s, about 90% of the typical speed of sound. The distance the blade travels in one rotation is pi*diameter. A copter with 2 x 20 ft blades would then be limited to 1000 ft/s / (pi*40 ft /revolution) = 8 revolutions/s At 8 rps, in 1/500 s, the blade only rotates 6 degrees, which is also what your picture appears to show! You'll need around a 1/16 s exposure (pi*bladelength/speedofsound/#blades) to get the full blade circle into your photo. Helicopter blade speeds are pretty easy to calculate! They need to stay under the speed of sound at the tips, else bad things happen. So, say they’re limited to 1000 ft/s, about 90% of the typical speed of sound. The distance the blade travels in one rotation is pi*diameter.

A copter with 2 x 20 ft blades would then be limited to
1000 ft/s / (pi*40 ft /revolution) = 8 revolutions/s

At 8 rps, in 1/500 s, the blade only rotates 6 degrees, which is also what your picture appears to show!

You’ll need around a 1/16 s exposure (pi*bladelength/speedofsound/#blades) to get the full blade circle into your photo.

]]> by: Yoko's Daddy http://regex.info/blog/2008-07-01/853#comment-18562 Wed, 02 Jul 2008 00:33:47 +0000 http://regex.info/blog/2008-07-01/853#comment-18562 Good morning. Thank you for yesterday. My family stays at this hotel in skiing every year. As for this story, it was made to hear from the person at the hotel last year. It is a foolish story at all. The purpose to do the foreign ministerial meeting in Kyoto is to save "Kyoto" face that was not able to take place G8 summit. So to speak, Japanese country paid Kyoto compensation money. Good morning. Thank you for yesterday.

My family stays at this hotel in skiing every year. As for this story, it was made to hear from the person at the hotel last year. It is a foolish story at all.

The purpose to do the foreign ministerial meeting in Kyoto is to save “Kyoto” face that was not able to take place G8 summit. So to speak, Japanese country paid Kyoto compensation money.

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