Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version 108819 Likes Search this Thread
06-28-2014, 06:46 PM   #9181
Loyal Site Supporter
Loyal Site Supporter




Join Date: Mar 2012
Location: Rochester, NY
Photos: Gallery
Posts: 5,327
Zombies!!!!!!!!! Well that does it for me. I have been trying to decide between a K3 and a shotgun. I guess I need to get the shotgun to defend against Zombies.

06-28-2014, 09:20 PM - 1 Like   #9182
Senior Member
karro's Avatar

Join Date: Mar 2014
Location: Riga
Photos: Albums
Posts: 245
QuoteOriginally posted by Racer X 69 Quote
No offense taken.

But.

Will a 645Z hit 150mph + on the straights?
wellll, let's see
Terminal velocity = Sqrt((2 * mass * g) / (air density * projected area * drag coeff))
Mass = 1.5kg (w/ batteries)
g =9.8
air density at +25*C (there's no point to experiment in the cold) - about 1.18kg/m3, humidity and change of t* depending on height are not taken into account

dimensions: 0.156 * 0.117 * 0.123m
for our purposes, let's round it to cube: .125 x .125 x .125
technically, the projected area changes all the time (rotation during the fall), but for our scientific purposes, let's assume, that it is falling down with one edge pointing downwards, so we have 2 sides projected at 45 degree angle.
Formula is: L x H * cos(angle) = .125*.125*cos(45) * 2 (since 2 sides are projected) = 0.022 m2 (cos(45) = .71)
drag coefficient for a cube is 0.8 (wiki it)

so, the result:
terminal velocity in air for 645Z = sqrt((2*1.5*9.8) / (1.18 * .022 * .8)) = 37.62m/s = 135.4km/h = 84.2mph

No. 645z can't do 150mph
06-29-2014, 02:59 AM   #9183
Master of the obvious
Loyal Site Supporter
savoche's Avatar

Join Date: Jun 2011
Location: Lowlands of Norway
Posts: 18,312
QuoteOriginally posted by karro Quote
No. 645z can't do 150mph
Of course a 645Z can do 150mph. It just needs to be propelled by sufficient force. Much like the Datsun, really. Or the early stages of bacon - they really can fly.

Ok, the 645Z might not travel in a straight (horizontal) line. Ballistics are rarely linear.
06-29-2014, 03:17 AM   #9184
Pentaxian
Jean Poitiers's Avatar

Join Date: Apr 2011
Location: Lost in translation ...
Photos: Gallery | Albums
Posts: 18,076
QuoteOriginally posted by gaweidert Quote
Zombies!!!!!!!!! Well that does it for me. I have been trying to decide between a K3 and a shotgun. I guess I need to get the shotgun to defend against Zombies.
Yep ... a 12 gauge automatic might be best ... too tiring to pump each time.

And while shooting, do NOT forget to play "Who's Next" as loud R&R back ground music !!!



06-29-2014, 03:40 AM   #9185
Master of the obvious
Loyal Site Supporter
savoche's Avatar

Join Date: Jun 2011
Location: Lowlands of Norway
Posts: 18,312
QuoteOriginally posted by Jean Poitiers Quote
Yep ... a 12 gauge automatic might be best ... too tiring to pump each time.
Nah, give me a proper catapult and a good supply of K-3s. I'm certain they would be more lethal to zombies (too) than a puny 12 gauge.

But "Who's next" is a good choice.
06-29-2014, 03:43 AM   #9186
Master of the obvious
Loyal Site Supporter
savoche's Avatar

Join Date: Jun 2011
Location: Lowlands of Norway
Posts: 18,312
Oh, just realised I stumbled upon a reason for getting a K-3. Rats.

Well, not literally rats. Zombies. But... Rats.
06-29-2014, 12:04 PM - 1 Like   #9187
Moderator
Loyal Site Supporter
Loyal Site Supporter
OrchidJulie's Avatar

Join Date: Jun 2012
Location: Magic City
Photos: Gallery | Albums
Posts: 7,006
Being bored one day, I actually read through the TOS for an online service that we use at work. It was -- surprise! -- a serious yawn-inducing document until I got to the part about their not being responsible for stuff like acts of God, war and the like. The list actually included "Zombie Apocalypse" as one of the events. I am not making this up!

Probably they will have to amend it to include Invasion of the hociR...

06-29-2014, 12:42 PM   #9188
Pentaxian
Jean Poitiers's Avatar

Join Date: Apr 2011
Location: Lost in translation ...
Photos: Gallery | Albums
Posts: 18,076
QuoteOriginally posted by OrchidJulie Quote
Being bored one day, I actually read through the TOS for an online service that we use at work. It was -- surprise! -- a serious yawn-inducing document until I got to the part about their not being responsible for stuff like acts of God, war and the like. The list actually included "Zombie Apocalypse" as one of the events. I am not making this up!

Probably they will have to amend it to include Invasion of the hociR...
It's already happening here ... micro Zombie Apocalypses!

Next one should start happening tomorrow at 18h00 Paris time ... game time.

Beat in the head of a Zombie with a K-3 will only render it more powerful ... France & Tokyo are dooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooomed!

(Kinda of like "Goooooooooooooooooooooooooooooooooooooooooooal!" there, n'est-ce pas?! )
06-29-2014, 12:48 PM   #9189
Moderator
Loyal Site Supporter
Loyal Site Supporter
OrchidJulie's Avatar

Join Date: Jun 2012
Location: Magic City
Photos: Gallery | Albums
Posts: 7,006
Here? Non. The "goooooooooooooooal!" announcer is somewhere in Latin America.

Wait,. Miami is somewhere in Latin America.... we're doomed, too...
06-29-2014, 05:23 PM   #9190
Pentaxian
Pioneer's Avatar

Join Date: Aug 2009
Location: Wandering the Streets
Photos: Gallery | Albums
Posts: 1,411
QuoteOriginally posted by monochrome Quote
I owned a K50/1.2 for about a year. I rarely used it wider than f/5.6 but focusing the bright image was great. Of course focusing the bright image of my K50/1.4 was also great. And I rarely use it wider than f/5.6 either. I don't miss the stop and enjoy the $575.

I guess I am benighted.
I love the view in my LX with the 50/1.2 is on board and the SA-23 screen in the viewfinder. If you have never experienced it you have not truly lived. And the photos ain't bad either.
06-29-2014, 05:35 PM   #9191
Loyal Site Supporter
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Working From Home
Photos: Gallery | Albums
Posts: 26,276
QuoteOriginally posted by Pioneer Quote
I love the view in my LX with the 50/1.2 is on board and the SA-23 screen in the viewfinder. If you have never experienced it you have not truly lived. And the photos ain't bad either.
No doubt. I think about few lenses I've sold. Vivitar 105/2.65 Macro very often. Pristine K135/2.5 with case and hood whenever I use the second copy I bought. K50/1.2 - I know I had it once. That's enough.
06-29-2014, 05:39 PM   #9192
Pentaxian
Pioneer's Avatar

Join Date: Aug 2009
Location: Wandering the Streets
Photos: Gallery | Albums
Posts: 1,411
QuoteOriginally posted by monochrome Quote
No doubt. I think about few lenses I've sold. Vivitar 105/2.65 Macro very often. Pristine K135/2.5 with case and hood whenever I use the second copy I bought. K50/1.2 - I know I had it once. That's enough.
I do enjoy my Vivitar 105 Macro. It has replace my other macro lenses with the exception of the 90-180 Vivitar flat field zoom.

I gave up selling lenses, that way there is no regret.
06-29-2014, 05:45 PM   #9193
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,451
You guys are taking lenses? That's dangerously close to being on topic... you guys like living ion the edge.
06-29-2014, 06:35 PM   #9194
Moderator
Man With A Camera
Loyal Site Supporter
Racer X 69's Avatar

Join Date: Jun 2010
Location: The Great Pacific Northwet, in the Land Between Canada and Mexico
Photos: Gallery | Albums
Posts: 28,077
QuoteOriginally posted by gaweidert Quote
Zombies!!!!!!!!! Well that does it for me. I have been trying to decide between a K3 and a shotgun. I guess I need to get the shotgun to defend against Zombies.
QuoteOriginally posted by Jean Poitiers Quote
Yep ... a 12 gauge automatic might be best ... too tiring to pump each time.

And while shooting, do NOT forget to play "Who's Next" as loud R&R back ground music !!!
QuoteOriginally posted by savoche Quote
Nah, give me a proper catapult and a good supply of K-3s. I'm certain they would be more lethal to zombies (too) than a puny 12 gauge.

But "Who's next" is a good choice.
QuoteOriginally posted by OrchidJulie Quote
Being bored one day, I actually read through the TOS for an online service that we use at work. It was -- surprise! -- a serious yawn-inducing document until I got to the part about their not being responsible for stuff like acts of God, war and the like. The list actually included "Zombie Apocalypse" as one of the events. I am not making this up!

Probably they will have to amend it to include Invasion of the hociR...
QuoteOriginally posted by Jean Poitiers Quote
It's already happening here ... micro Zombie Apocalypses!

Next one should start happening tomorrow at 18h00 Paris time ... game time.

Beat in the head of a Zombie with a K-3 will only render it more powerful ... France & Tokyo are dooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooomed!

(Kinda of like "Goooooooooooooooooooooooooooooooooooooooooooal!" there, n'est-ce pas?! )
Now you all really need a couple of these for the Zombie Apocalypse.

06-29-2014, 06:51 PM   #9195
Moderator
Man With A Camera
Loyal Site Supporter
Racer X 69's Avatar

Join Date: Jun 2010
Location: The Great Pacific Northwet, in the Land Between Canada and Mexico
Photos: Gallery | Albums
Posts: 28,077
QuoteOriginally posted by karro Quote
wellll, let's see
Terminal velocity = Sqrt((2 * mass * g) / (air density * projected area * drag coeff))
Mass = 1.5kg (w/ batteries)
g =9.8
air density at +25*C (there's no point to experiment in the cold) - about 1.18kg/m3, humidity and change of t* depending on height are not taken into account

dimensions: 0.156 * 0.117 * 0.123m
for our purposes, let's round it to cube: .125 x .125 x .125
technically, the projected area changes all the time (rotation during the fall), but for our scientific purposes, let's assume, that it is falling down with one edge pointing downwards, so we have 2 sides projected at 45 degree angle.
Formula is: L x H * cos(angle) = .125*.125*cos(45) * 2 (since 2 sides are projected) = 0.022 m2 (cos(45) = .71)
drag coefficient for a cube is 0.8 (wiki it)

so, the result:
terminal velocity in air for 645Z = sqrt((2*1.5*9.8) / (1.18 * .022 * .8)) = 37.62m/s = 135.4km/h = 84.2mph

No. 645z can't do 150mph
I see.

Very nice explanation too!
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
bacon, bagpipes, beer, breakfast, canada, catch 22, cheese, drink, dslr, ford, general talk, gin, guns, igunaq, k-3, k-mount, k3, kids, lutefisk, lycra, marital relations, pentax k-3, possums, sandwich, scotch, shirley, snoring, spam, squirrels, tokyo

Similar Threads
Thread Thread Starter Forum Replies Last Post
why I will buy a K3 chicagojohn Pentax K-3 & K-3 II 80 09-18-2016 08:42 AM
Suggestion Neutralize the 'why I won't buy a k-3' thread crewl1 Site Suggestions and Help 61 10-04-2014 05:08 PM
Why I Won't Be Buying A K5IIs Racer X 69 Pentax K-5 & K-5 II 40 02-03-2014 08:12 PM
Why I don't buy Pentax lenses keyser Pentax SLR Lens Discussion 44 12-20-2012 01:58 AM
I feel so old: 8 things the facebook gen won't buy Nesster General Talk 27 04-22-2012 11:01 AM



All times are GMT -7. The time now is 04:59 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top