I am not totally screwed up. I am a Ph.D. candidate in Chemistry and have taken more science/physics classes than I care to admit. Are you saying all of the experiments done in a physics lab demonstrating the laws you are describing are bogus? If you want a "figure", I don't know what it is. I DO know however that force=massxacceleration. A car with a certain mass going at a certain speed (acceleration) hitting another car doing the same speed in opposite direction will encounter a GREATER force than one hit a stationary mass (ie wall) that is not moving. Might not be exactly "twice", but it is a hell of a lot greater than hitting a stationary wall.

 

Your teachers were wrong.

The reason the clay compressed twice as much when using two hammers is because it had to adsorb twice the energy – two hammers two times the energy, each hammer shares that energy. Put another way... The face of each hammer in your double test transferred the same energy as the single hammer.

 

Energy is neither created nor destroyed. It can be transferred which is what is happening and you are on track with what you just said

It's more complex as it involves kinetic energy, momentum and force.

 

Fractaldragon:

Please, PLEASE give it up. If you've taken a second-year dynamics course (which you obviously HAVEN'T), this would be as obvious as looking up in the sky and seeing "blue".

Without the the basic engineering background (physics ain't gonna get you there), it's mystifying, as you just have to rely on intuition.

Intuition is usually worthless. Particularly in this case.

 

fractal, your kinda right, but what if you hit a .. . . soccar ball at 60 mph, see it all depends on the mass of the object. If its equal mass, and equal speed, its basically a wall. If the product of the mass and the speed is greater than the product of your mass and speed, then its more than a wall.

 

You are exactly right Poor choice of words on my part should have said transferred not absorbed

 

As I was reading the thread and thinking the exact same thing. Speed belongs at the track. I too have loved ones out on the roads and would take the person out that killed them by driving like a d@mned fool.

No sympathy for the L driver from me.


Rocks

 

It sounds like we have some people here with some knowledge on these issues so I am going to throw out a question about something I was told years ago.

My moms family lost one of their brothers in a head on crash in the late fifties. The story they all tell goes like this. Witnesses to the crash say the fellow that hit their brother sped up just before impact. My moms family goes on to say that they where told by one of the investigating offecers at the time that by speeding up, the other driver probably saved his own life due to the fact that the car that their brother was driving took the biggest hit since he was hitting the brakes.

Is there anything to this or was this even something that may have been true back then due to the heavier made cars?


Rocks

 

'Rocks:

NO WAY would speeding up before impact improve one's chances of surviving a crash, especially in the DEATHTRAPS that were called an automobile in "the old days". Completely the opposite. Your peeps were fed a steaming pile, as these things go.

Today's vehicles, no matter how small and cheap, are INFINITELY more safe than the POS rigid, un-engineered, no-seatbelted, no-airbagged, steering-column-impaling, non-safety-glassed, non-crumple-zoned, bursting-into-flames, engine-through-the-firewall, hard-dashed, seat-anchor-breaking, door-popping-open, yadda-yadda-yadda crap that was rolling a generation ago.

Word.

 

I’m sorry to hear of your family’s loss. If the accident was a head on impact then either vehicle increasing its velocity would increase the total energy that must be transferred at time impact. Velocity of either vehicle increasing makes it worse for both drivers.

 

LMAO at the description of the old cars......that does describe them well.

Thanks for the answer. I probably won't make any attempts at straightening out my moms family at the next reunion...LOL. They have been telling that story so long, it would cause me to be hanged at sunrise.


Rocks

 

SGL did handle that in a bit more sensitive manner than I. My condolences as well. Damn.

SGL - thanks for backing me up as the voice of understanding all night. What is you r educational background? MSChE here and MSEE wife. Both LONG experienced R&D / product testing engineers.

 

When they get to telling that story, they always act as if the guy sped up on purpose. I always suspected he just panicked and hit the gas instead of the brake. But like I said in my last post, I never really felt brave enough to challenge them on it. There are 6 sisters and 2 brothers in that bunch.


Rocks

 

Well, at least Fractaldragon isn't flogging his ignorance of the basic laws of the universe any longer on this thread.

Thank the Creator for small miracles.

 

I rammed a tree doing 80 Km/h (50 some odd miles per hour) I just called the dog and walked away. I hit a stationary object. If another F-150 was comeing at me how much worse would this be?. and would I of walked away? I just have grade 12 and that is it. I' am as dumb as the tree I hit .

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