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Redneck human slingshot!!!


Ivan280zt

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Darwin award candidates for sure!!!

 

The best one I've ever witnessed was at blasting school back in the 80's. 3 darwin award candidates stole some dynamite and electric caps (#7's) and decided to go fishing. One was holding a video camera, one put a #7 cap in a stick of dynamite that was wired to some electric wire. The other was to put the ends to a car battery. The guys thought that they would touch the wires, then the other would throw the stick into the river and they'd wait 7 seconds for it to go off and then they'd have some fish.

 

Well, dynamite delay fuses or caps are rated in milliseconds not seconds.

 

Good thing the camera man wasn't standing too close to the 2 stooges, but it was captured on film and showed to us at school. 2 less morons in the world today.

 

Priceless.

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So... the two stooges fed the fish instead of the other way around. Hah!!

 

...3 darwin award candidates stole some dynamite... and decided to go fishing." *>]BOOM[<*
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The givens must change - 125# Kentucky lass is okay but 1000# worth of red neck and vehicle should be 800#, 200# for each manslaughter potential redneck & 400# for the vehicle.

Tractive effort is Fn(fc). Normal force times traction coefficient.

Normal force @ rear wheel = 400#(.6)(vehicle 40%front/60%rear split) + 200#/2 (dumb driver front/rear split – 50%) + 200# (dumb cut-her-loose person who is over rear wheel) = 540# = Fn.

fc of .8 is reasonable for rubber knobby tires on grass.

Tractive force would be 432# if we agree (But you are the boss after all!).

Now, as the buggy stretches the bungee the bungee starts to lift the rear of the buggy. When that lift diminishes normal force so lateral component of the bungee pull matches available traction, the buggy’s wheels spin and the buggy stalls.

This is a looooooong example –

To solve this properly we need the spring rate of the bungee and I can’t find that. That’s what allows us to calculate the bungee angle. Please read on. . .

If the buggy gets 400# of pull laterally, then at a 15 degree angle (I made this up) the bungee is lifting with 103# force which diminishes normal force to 437#(540# – 103#)and with a friction coefficient of .8 the buggy is only capable of 349# pull. The buggy would have wheel spin already.

That’s why the buggy does this mad dash, it needs momentum to get more pull than going slow would allow! The video shows the back end of the buggy lifting (watch it again).

So assuming 400# pull is a reasonable achievement, then the instantaneous acceleration @ release is

Ax = F/M = 400#/3.88 slugs (125#/32.2) = 103 ft/sec2

G’s is 103’/sec divided by acceleration of gravity (32.2) and that would be 3.2 g’s.

The video show’s looks like a little more than this, but not much.

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