Impact formula - Page 5

# Thread: Impact formula

1. ## Re: Impact formula

If you fire from West to East your 1,200 feet per second muzzle velocity round will actually be moving at approxiamtely 2,500 feet per second on average around the earths axis depending on how far or near you are to the equator. If you fire from East to West your 1,200 feet per second muzzle velocity round will be moving only 100 feet per second in the opposite direction in which you fired it around the earths axis.

Sincerely,

William McCormick

2. ## Re: Impact formula

Originally Posted by Insaneride
William McCormick, the gyro effect does have an effect on the bullet but gravity remains the same. You care to further explain
I posted at the end of the thread about escape velocity. Firing East to West as opposed to West to East.

Sincerely,

William McCormick

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## Re: Impact formula

Originally Posted by Insaneride
The Earth's escape velocity is 25,030 miles per hour or 3,700 feet per second. Ironically, the Earth has a circumference of approximately 25,000 miles or the escape velocity in mph. This irony Probly doesn't apply using the metric system tho.
William McCormick, I think you were referring to my math and yes I got a decimal place wrong. The escape velocity should be 37,000 feet per second to escape Erth's gravity.

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## Re: Impact formula

Originally Posted by William McCormick
If you fire from West to East your 1,200 feet per second muzzle velocity round will actually be moving at approxiamtely 2,500 feet per second on average around the earths axis depending on how far or near you are to the equator. If you fire from East to West your 1,200 feet per second muzzle velocity round will be moving only 100 feet per second in the opposite direction in which you fired it around the earths axis.

Sincerely,

William McCormick
I see what you are saying but, what if you are driving east to west or vice versa, would that logic still apply? What if you threw a ball out the window while moving at 60mph traveling west, would the ball be traveling in negative miles per hour?

5. ## Re: Impact formula

Originally Posted by Insaneride
I see what you are saying but, what if you are driving east to west or vice versa, would that logic still apply? What if you threw a ball out the window while moving at 60mph traveling west, would the ball be traveling in negative miles per hour?
Yes the ball thrown east to west is traveling at negative 1,100 to 1,300 feet per second around the earths axis, on average depening on where you are, depending on how you average it, like most square feet of the earths surface or by the distance between poles and the equator.

Sincerely,

William McCormick

6. ## Re: Impact formula

Originally Posted by MinnesotaDave
I actually had the same question twice when I went to college.
I think you'll find that his textbook contains questions similar to below.

First time it was an arrow aimed directly at the monkey. In other words, no arc for proper shot placement.
In this slower scenario it's easier to visualize that gravity will affect both monkey and arrow over what ever time period it takes the arrow to get to the monkey.
Other possible variables are also neglected in this simplistic style question.

The second time it was a bullet. Also aimed directly with no arc for proper shot placement.
The time is much shorter, but to the same end.
Again, any other possible variables are neglected.

An additional question, preceding the other two, was the classic:
"Which bullet hits the ground first? One aimed parallel to the Earth, or one dropped at the same time as the other is fired."

Now, in my opinion, this question has to neglect the curvature of the Earth to assume a bullet could be fired "parallel."

The wording of the question is critical.

It's very common for students to "read into" a question based on personal tangible experience, instead of taking the beginning fundamental questions at face value.

This is where the teacher's pre-loading of the thought process is important. Students have to be made to understand that math/physics always starts with the fundamental style questions before adding in the complexity of additional variables.

If the teacher does not do this, students can easily misunderstand what is being asked.
I always sighted at 50 yards for my 30-06 rifle, at 100 yards I would be slightly high, at 200 I would always be high and to the right. At three hundres hards I was almost dead on maybe slightly high and at four hundred I was dead on.

Sincerely,

William McCormick

7. ## Re: Impact formula

When shooting chrome hub caps laid against a sand wall, at 400 yards, they would jump up and spin, like flipping a coin. I would fire while they were in the air and aim under them, and hit them every time. But I had the best Simmons scope I could buy at the time. The lens was large in diameter. So it let in a lot of light and gave a fantastic field of view even when zooming in, so you would not lose sight of the moving target. A friend and Marine weapons expert, checked it out one day, and he just kept laughing as he was targeting things in dark places.

Sincerely,

William McCormick

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## Re: Impact formula

Originally Posted by William McCormick
When shooting chrome hub caps laid against a sand wall, at 400 yards, they would jump up and spin, like flipping a coin. I would fire while they were in the air and aim under them, and hit them every time. But I had the best Simmons scope I could buy at the time. The lens was large in diameter. So it let in a lot of light and gave a fantastic field of view even when zooming in, so you would not lose sight of the moving target. A friend and Marine weapons expert, checked it out one day, and he just kept laughing as he was targeting things in dark places.

Sincerely,

William McCormick
You know the surface of the earth at sea level is about 4000 miles/ or 6400Km (metric) from the center of our Earth? Doesn't that gear things down?

At Equator
Last edited by Insaneride; 06-23-2019 at 10:18 PM. Reason: At Equator tho

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## Re: Impact formula

Does a bird flying east flap its wings more or less to go the same speed as a bird flying west??

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## Re: Impact formula

Depends on the wind speed..... and if you mean airspeed or groundspeed or..... earth rotationally corrected ground speed

Wow!!

12. ## Re: Impact formula

Originally Posted by Willie B
I know this teacher was unwilling to entertain the concept that bullets don't fall short range because sights compensate. She was upset that a student understood where she did not. Someone had to pay. Despite having time to research, she still considered his claim that bores are not parallel to sights to be "ridiculous" She carried her presumption to the parent conference still willing to fight it out. She was wrong, and unwilling to admit it.

What amazes me is that hundreds of students before Zack never challenged her.

I can prove that 10 bullets fired from a rifle at 100 yards can hit near bullseye showing little evidence of the effects of gravity. A monkey will fall, few will argue.
I used to get escorted to the principles office weekly, haha, for telling the teacher she did not know what she was teaching. Most teachers live in a magic bubble where only their reality is real. She got so mad one time she used derogatory words to describe me to the other students that she asked to explain the problem to me. When she got back four different and wrong answers she realized she not only did not understand but she had caused a misunderstanding in the other kids as well. Then she used a derogatory term to describe them. I think it was with fractions and she did not know why she was inverting the fraction in some cases and not others and where to put the variable. It was a bit disheartening. The good thing was I knew she didn't get a real education, so I just dismissed here, some kids got messed up, they were never the smiling kid with their hand up again. So sad not the teacher's fault either, she was given a vacuum of knowledge and forced to memorize and fill that vacuum with anything they gave her, to get her glorious degree.

Sincerely,

William McCormick

13. ## Re: Impact formula

Originally Posted by Fast Leroy

In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.

Inertia is an intrinsic characteristic of the object related to its mass. Inertia tells you how much force it will take to cause a particular acceleration on the object. Momentum is a function of an object's mass and velocity. Momentum is a measure of the kinetic energy of the object.
Momentum isnt exactly a good measure of kinetic energy.... Its a good measure of energy exchange in collisions and braking time and stuff...

Consider a strong man pushing a 50,000kg train car at 0.5 m/s (about 1.5ft/sec)
Consider a car with mass 1000kg and speed 25m/s (55mph)

It takes so little kinetic energy, maybe 300watts to push the train car that a person can do it.
It takes nearly 70,000 watts of energy to run the vehicle at 55mph.

The momentum of the train car is 25,000 units. KE = 10,000 Joules
The momentum of the car is 25,000 units. KE = 625,000 Joules

If the train car and the car crashed into each other face on (in an inelastic collision), they would cancel each other out, yet their kinetic energies are VASTLY DIFFERENT. A human being can push the train car, yet it takes a strong engine to push the car at that speed, yet in a collision, they cancel each other out. If you looked at Momentum and Kinetic Energy are completly different..... In these collisions, KE is not conserved.
Last edited by n00b; 10-23-2019 at 06:49 PM.

14. ## Re: Impact formula

Originally Posted by n00b
Momentum isnt exactly a good measure of kinetic energy.... Its a good measure of energy exchange in collisions and braking time and stuff...

Consider a strong man pushing a 50,000kg train car at 0.5 m/s (about 1.5ft/sec)
Consider a car with mass 1000kg and speed 25m/s (55mph)

It takes so little kinetic energy, maybe 300watts to push the train car that a person can do it.
It takes nearly 70,000 watts of energy to run the vehicle at 55mph.

The momentum of the train car is 25,000 units. KE = 10,000 Joules
The momentum of the car is 25,000 units. KE = 625,000 Joules

If the train car and the car crashed into each other face on (in an inelastic collision), they would cancel each other out, yet their kinetic energies are VASTLY DIFFERENT. A human being can push the train car, yet it takes a strong engine to push the car at that speed, yet in a collision, they cancel each other out. If you looked at Momentum and Kinetic Energy are completly different..... In these collisions, KE is not conserved.
A huge concept I will go to my grave never understanding.

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16. ## Re: Impact formula

Originally Posted by William McCormick
If you fire from West to East your 1,200 feet per second muzzle velocity round will actually be moving at approxiamtely 2,500 feet per second on average around the earths axis depending on how far or near you are to the equator. If you fire from East to West your 1,200 feet per second muzzle velocity round will be moving only 100 feet per second in the opposite direction in which you fired it around the earths axis.

Sincerely,

William McCormick
It's all relative.... Relative to where the measurements are taken from. If your standing on the earth the velocity of either round will be measured at 1,200 fps. If the measurement is taken from space, not on the earth then your explanation is correct.

17. ## Re: Impact formula

Originally Posted by n00b
Momentum isnt exactly a good measure of kinetic energy.... Its a good measure of energy exchange in collisions and braking time and stuff...

Consider a strong man pushing a 50,000kg train car at 0.5 m/s (about 1.5ft/sec)
Consider a car with mass 1000kg and speed 25m/s (55mph)

It takes so little kinetic energy, maybe 300watts to push the train car that a person can do it.
It takes nearly 70,000 watts of energy to run the vehicle at 55mph.

The momentum of the train car is 25,000 units. KE = 10,000 Joules
The momentum of the car is 25,000 units. KE = 625,000 Joules

If the train car and the car crashed into each other face on (in an inelastic collision), they would cancel each other out, yet their kinetic energies are VASTLY DIFFERENT. A human being can push the train car, yet it takes a strong engine to push the car at that speed, yet in a collision, they cancel each other out. If you looked at Momentum and Kinetic Energy are completly different..... In these collisions, KE is not conserved.

There are other variables involved though. Since there is no such thing as an inelastic collision it kind of makes the whole thing a bit unreal. There is a set of laws in our universe about, start change and stop. You cannot change an object without starting or stopping it both require time. When things are moving fast, time can mean an added destruction or force applied to an object because it is impossible to reverse an object's direction instantly. When you look at the hood of your car and see what the bugs have done to your paint that is the effect of start, change, and stop. When two objects are heading towards each other and stike each other there is going to be an elastic collision no matter what. Even the paint that is moving in one direction before it can change direction and absorb some impact has to stop, that is when the damage to the paint occurs. For that split second the paint is harder than glass and more brittle.

That is why so much of the safety and accident information is flawed and just plain wrong, because they no longer take into consideration start, change and stop. There is no velocity no material that is not bound by start, change, and stop.

Sincerely,

William McCormick

18. ## Re: Impact formula

Originally Posted by Willie B
School me in the math of inertia.

I lay 1 LB on the head of a nail nothing happens. If I swing a 1 LB hammer at a high rate of speed taking advantage of leverage to speed its travel I can effectively drive it with a few blows.

A 180 grain bullet hits a gallon of paint at 500 FPS, it might not even leak. If it hits at 2000FPS, the can explodes.

The Karate black belt smashes cement blocks with his bare hands, Or I can swing a short 2x6, hit it on a rock and break it in half.

Old time wood splitters slammed the block at speed making them more effective at both splitting wood, and removing human limbs.

How is this calculated?
With bullets, we found there is an electrical effect after a certain velocity that allows them to plasma cut through steel. This is why an aluminum airplane can cut through steel H-beams if it is moving at a high velocity. We live in an all-electric universe, it used to be taught that way in American schools. That graphic of particles of electricity racing around the nucleus of an atom is part of the counterintelligence campaign in the U.S. and England, which started after World War Two. It was to hide the secret of the atom and atom bomb from the citizens of earth. Leaving us with non-citizens leading the world. There is no attraction force in our universe only pushing forces, all particles and matter repel one another. It used to be taught up until 1973 that there is only one sub-matter particle the particle of electricity. The nucleus of an atom was taught to be a sphere of particles of electricity held in that shape by the ratio of area to the volume of a very small sphere. It was taught there is an infinite number of particles of electricity in a proton very much like atoms in the sun, all repelling all the time.

We all need to be on the same page with stuff like that before you can figure out much of anything to a standard.

Sincerely,

William McCormick

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