by karlamagallanes
Friday, 11 January 2013
Wednesday, 9 January 2013
Monday, 17 December 2012
Wednesday, 12 December 2012
Cool Hat Bro
Cool Hat Bro:
You're a very fashion fowards, err, backward guinea pig. There must be a cool story behind how you got that hat, we'd all love to hear it.
-Sally Squeeps
-Sally Squeeps
Squee! Spotter:
Unknown
Unknown
Saturday, 8 December 2012
Scampering
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Scampering
Hey there baby koala! Where are you going? COME BACK AND LET US SQUEE OVER YOU!
-Sally Squeeps
Squee! Spotter:
Unknown
[ iMoo 2 ]
Thursday, 22 November 2012
(title unknown)
(title unknown):
And with the help of her kitty friend, she builds an army made of discarded robot scraps and they take over the world. But this will probably be another comic :)
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Oh, and Happy Thanksgiving! See you next week!
And with the help of her kitty friend, she builds an army made of discarded robot scraps and they take over the world. But this will probably be another comic :)
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Oh, and Happy Thanksgiving! See you next week!
Tuesday, 20 November 2012
Machine Gun Jetpack
I love the drawing of the cop pulling him over :D
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Machine Gun Jetpack
Machine Gun Jetpack
"Is it possible to build a jetpack using downward firing machine guns?"
—Rob B
I was sort of surprised to find that the answer was yes! But to really do it right, you'll want to talk to the Russians.
The principle here is pretty simple. If you fire a bullet forward, the recoil pushes you back. So if you fire downward, the recoil should push you up.
The first question we have to answer is "can a gun even lift its own weight?" If a machine gun weighs ten pounds but only produces eight pounds of recoil when firing, it won't be able to lift itself off the ground, let alone lift itself plus a person.
In the engineering world, the ratio between a craft's thrust and the weight is called, appropriately, thrust-to-weight ratio. If it's less than 1, the vehicle can't lift off. The Saturn V had a takeoff thrust-to-weight ratio of about 1.5.
Despite growing up in the South, I'm not really a firearms expert, so to help answer this question, I got in touch with an acquaintence in Texas. (Judging by the amount of ammunition they had lying around their house ready to measure and weigh for me, Texas has apparently become some kind of Mad Max-esque post-apocalyptic war zone.)
As it turns out, the AK-47 has a thrust-to-weight ratio of around two. This means if you stood it on end and somehow taped down the trigger (Note: Please, PLEASE do not try this at home) it would rise into the air while firing.
This isn't true of all machine guns. The M60, for example, probably can't produce enough recoil to lift itself off the ground.
The amount of thrust created by a rocket (or firing machine gun) depends on (1) how much mass it's throwing out behind it, and (2) how fast it's throwing it. Thrust is the product of these two amounts:
\[\text{Thrust}=\text{Mass ejection rate}\times\text{Speed of ejection}\]
If an AK-47 fires ten 8g bullets per second at 715 meters per second, its thrust is:
\[10\tfrac{\text{bullets}}{\text{second}}\times8\tfrac{\text{grams}}{\text{bullet}}\times715\tfrac{\text{meters}}{\text{second}}=57.2\text{ N}\approx13\text{ pounds of force}\]
Since the AK-47 weighs only 10.5 pounds when loaded, it will be able to take off and accelerate upward.
In practice, the actual thrust turns out to be up to around 30% higher. The reason for this is that the gun isn't just spitting out bullets—it's also spitting out hot gas and explosive debris. The amount of extra force this adds varies by gun and cartridge.
The overall efficiency also depends on whether you eject the shell casings out of the vehicle or carry them with yo...
[ iMoo 2 ]
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