Physics/math formula guru question

Grumpy

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
Physics/math formula guru question
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Talking about an accident where a Nissan Sentra(3100lbs) was going 20mph and rear ended a 1/2 ton pick up(5400lbs) that was pulling a flatbed trailer(1800lbs). Pick up was stopped and Nissan rear ended it, tearing the trailer up, bending the receiver /ball and bending the pick up frame where the hitch bolts to it and moving the truck about a foot. A Judge cannot understand how this “little tiny Nissan” going 20mph damaged the pick up frame from impacting the trailer. Who can figure the force of impact on this deal?
19DB8B43-FF7D-4A59-AF8B-0C53DD7BB93F_zpsrlgcp2ml.jpeg
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as an engineer, I can figure the related stated math, but theres a great deal of the facts not in evidence.

given the stated figures
29.33 Feet per second = 19.9977 Miles per hour
7000 grains=1 lb
3100x 7000=21700000 grains

21700,000 x 29.33 x29.33 /450240= 41,461 ft lbs of energy on impact
56213.56795576817 nm

thats roughly 13.4 times the weight of that nissan nearly instantly applied to the trailer impact point and much of that energy directly applied to the trailer hitch,


but in truth you have no way of knowing, for a fact,
the guy was not going 30-40 mph,
nor the actual, the true weight of the nissan and contents weight,
which could nearly quadruple the impact energy
https://www.convertunits.com/from/lb-ft/to/N-m
__________________
 
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Judge has no reason to question such as he is not mathematically intelligent.

Take a beer keg gas tank on a T-Bucket with 20 gallons of fuel in it and come to an abrupt stop like that wreck and see how well the brackets are that mount that keg.
Fuel approximately 8 pounds per gal and it will turn into a missile/bomb if it comes loose from that Bucket.
 
Uh, are we talking about someone I know???

T-Test said:
Take a beer keg gas tank on a T-Bucket with 20 gallons of fuel in it and come to an abrupt stop like that wreck and see how well the brackets are that mount that keg.
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Those straps are the same straps that held the gas tank in my 67 Chevelle. :)
 
No Rick, I was talking about how I mounted mine with square tubing welded to tank and the bolted to chassis so mine wouldn't become a missile.Scan4_0004_0001-1.jpg
 
My oldest son wrecked in 2005 running 55 mph on a 4 lane and blew left front tire and went across median. hit guard rail, spun 180* hit rail again and rolled onto right side. Windshield and seat belt saved his life. I looked for whatever he hit in the road, but couldn't find it. Busted his right knee on the dash (ss) was his only injury. Car not so good. EST $10,ooo damages. Just Liability at that time. Started another a few months later and finished in 30 days.

I have more pics--but it aint pretty.
 
yeah, its a damn shame that so many guys can tell you true stories of how they spent years or even decades building a dream car,
only to have it destroyed in a wreck, I know one guy that had a hemi road runner t-boned ,when some drunk ran a red light and turned into scrap.
the insurance did not come close to the cost and they would not allow him to buy the wreck back.
another guy I used to know was filling his gas tank in a gas station when the car next to his backed out carelessly, backing into his vette,
severely damaging his 1967 big block corvette,even worse it caught fire and was a total loss.
again insurance was not close to what he had into the car.
 
Mine is now insured for triple what I have in it. Now I can't tear it up and damn sure don't want to be in a wreck with it, unless somebody hits it when I'm inside eating some where. Just driving the wheels off of it down on the beaches and to the mountains and most every where East of the Mississippi River. Only trailer-ed it to Fla. once and to Tenn. once. Age/wind/sun are the only factors for the rest of our lives as to where we drive it.
 
Your son is very lucky he survived that crash!

How did you get another TBucket built in just 30 days?
 
Your Son was lucky.

Thats the Bad thing about those old T- buckets.
A wreck and your likely going to Die.

No Rollcage.
No NHRA Safety Gear .
Virtually none are safe for faster than 13s.
 
Reminds me of the story of my late Bud Bill told me many times.
Him wrecking his brand new 1968 L88 Corvette at 155 mph.
He was doing a top end run at night.
3.73 gears in diff.
Muncie M22.
Redline foot on the floor.
He was watching the speedo hover around 155.
Wanted to see 160 mph on the speedo.
Came up to what is called the Old Stage Curves local.
Hit gravel in the middle of the road.
Vered off course into a ditch and out.
Went over Telephone power lines 30 feet.
Landed in the cornfield.
Horrendously loud noises and then he blacked out.
Came to. All alone.
Seen stars above.
Assumed he was dead.
Tried to stand up but he could not.
Seat belts held him down.
Corvette body gone.
Just the drivers seat and main Corvetre frame left with a Smoking steaming L88 BBC still Hot.
He was 1/2 mile from the main road.
L88 just 1 day old.
1968 was the year for Bill.

Probably why so few Race Corvettes.
Chicken.
Takes a Real Man to do it.
 
OK, math again.
2 cars going opposite directions (say 60 mph) on a highway hit each other head on.
Is that impact equal to 1 car hitting a concrete wall at 120 mph?
 
Indycars said:
Your son is very lucky he survived that crash!

How did you get another TBucket built in just 30 days?
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Yes he was and he was doing 55 mph on a 4 lane highway. But you can also die in a teaspoon full of water. Woulda/couda/shouda just his lucky day.


I once was a mechanic/technician (35) years and had a welder/machinist degree. No job saved up parts and a few pieces of steel and a comercial sewing machine for the interior. $50.00 for inyerior and less than $2000.00 for the rest of the car except tires. Already had another set of wheels.

Back when I was younger, I could build anything if you gave me plans/dimensions or a thought sometimes and I would build/make it.

When I was under contract for the Army, I built a twin cylinder engine for one of Spec Ops Teams out of a 2foot by 2 foot chunk of aluminum, with split cases kinda like a Harley but with a rear end that a tranny could be bolted up to. That took me 90 days to do and that thing was scary to drive, and then I added a A.I.R. pump (smog) to it and played with the boost until it finally straightend out at 9. lbs of boost.

I've had fun my whole life doing this kinda stuff----but it's getting harder to do without using computers and such.
 
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