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Type: Posts; User: pikpobedy

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1. ## Thread: "Regaining momentum takes three times as much energy as sustaining momentum" - explanation please!

by pikpobedy
Replies
62
Views
2,663

### Impulse and momentum have the same base units....

Impulse and momentum have the same base units. Are they the same thing? hmmm
Torque and energy have the same base units. Are they the same thing? hmmm
Interesting when using dimensional analysis to...
2. ## Thread: "Regaining momentum takes three times as much energy as sustaining momentum" - explanation please!

by pikpobedy
Replies
62
Views
2,663

### It's a figure of speech. A metaphor for...

It's a figure of speech. A metaphor for motivation. A bunch of buzzwords. Also known as BS.
Maintaining momentum can be anywhere from nothing to almost everything.
Freefall in a vacuum, walking...

by pikpobedy
Replies
33
Views
3,164

### Plastic deformation is permanent deformation....

Plastic deformation is permanent deformation. Solids can flow under pressure. For example toothpaste, peanut butter, putty, clay, lead, aluminium, copper, steels, polyamide etc can be made deformed...

by pikpobedy
Replies
33
Views
3,164

### The rifle barrel is grooved. The bullet...

The rifle barrel is grooved. The bullet (projectile) is deformed from a circular cross section into one that is the "mate" of the grooved interior of the barrel. Thus a bit of squeezing and plastic...

by pikpobedy
Replies
33
Views
3,164

### I have an off qestion remark about the calibre of...

I have an off qestion remark about the calibre of a gun. In the article you posted on this, in the image, the 22 bullet looked to be so much smaller in case diameter than a 223 did, so the calibre as...

by pikpobedy
Replies
33
Views
3,164

### Mass is quantity of matter. It is independent of...

Mass is quantity of matter. It is independent of gravitational field. Force is mass x acceleration. Weight on earth is mass x gravitational acceleration.

by pikpobedy
Replies
33
Views
3,164

### Outer space as in interplanetary space is better...

Outer space as in interplanetary space is better vacuum than anything artificially made.

The mass of the ammunition in this case is important. A rifle round (aka cartridge) is comprised of a...

by pikpobedy
Replies
33
Views
3,164

### There is no point in continuing if you cannot...

There is no point in continuing if you cannot read and understand what I wrote. Sorry.
I asked you to do things and you persist in ignoring the instructions.
This is not a place where slaves do...

by pikpobedy
Replies
33
Views
3,164

### Muzzle energy - Wikipedia, the free encyclopedia...

Muzzle energy - Wikipedia, the free encyclopedia

From rifle ballistic table a 0.600 caliber rifle is 1950 fps / 7596 ft lbs at muzzle

How much energy to you need get your mass up to 7 miles...

by pikpobedy
Replies
33
Views
3,164

### Look up the muzzle energy of a 0.600 rifle...

Look up the muzzle energy of a 0.600 rifle bullet. See if 540 000 of that can accelerate a 10 pound rifle to escape velocity. Start with that.
11. ## Thread: Walter Lewin at his best

by pikpobedy
Replies
0
Views
1,637

### Walter Lewin at his best

Chuckle chuckle. This is funny on so many levels. The last minutes are hilarious. He has some Einstein in him.

Air Pressure Can Crush with Walter Lewin

by pikpobedy
Replies
3
Views
1,589

### I was at a Surface Mount Technology Association...

I was at a Surface Mount Technology Association conference a few years back. One of the guys there was working on nano-solder.
I found this: Development of Nano Lead Free Solders

As for your...
13. ## Thread: Explaining simple harmonic motion

by pikpobedy
Replies
16
Views
1,028

### "t=0 when the spring is displaced by x. The...

"t=0 when the spring is displaced by x. The spring takes four seconds to return to equilibrium. This is when the restoring force kicks in."

I take it that you state the equilibrium point is where...
14. ## Thread: Age of the universe

by pikpobedy
Replies
11
Views
2,363

### Where is the energy from "old" light going? ...

Where is the energy from "old" light going?

Is the Universe Leaking Energy? by Tamara M. Davis in Scientific American July 2010.

The article was scanned or otherwise reproduced in...
15. ## Thread: Walter Lewin Kirchhoff's rule is for the birds

by pikpobedy
Replies
3
Views
2,109

### tk421 I corrected myself viz the spelling...

tk421

I corrected myself viz the spelling issues.

As for the "over education" falderal. There are categories of posters who name drop and concept drop some with intimate understanding of and...
16. ## Thread: Walter Lewin Kirchhoff's rule is for the birds

by pikpobedy
Replies
3
Views
2,109

### Walter Lewin Kirchhoff's rule is for the birds

A few weeks I looked for these youtubes so as to insert in another thread.
I had forgotten the lecture names so I never found it then... but I found it a few minutes ago.

Kirchhoff's rule is...
17. ## Thread: Formula For Flight Time of RC Helicopter - FUN!

by pikpobedy
Replies
7
Views
1,449

### Hello, We sometimes get great problems like the...

Hello,
We sometimes get great problems like the one you pose, where a real situation, with real limitations of the equipment are brought up.
The battery weight is a significant part of the total...
18. ## Thread: Newton's Third Law and Collisions

by pikpobedy
Replies
25
Views
1,929

### Careful. Perfectly elastic also means absolutely...

Careful. Perfectly elastic also means absolutely no loss of energy into the environment. No noise, no heat, no everything in or out of those two balls. The P and KE equations hold perfectly.
Very...
19. ## Thread: Formula For Flight Time of RC Helicopter - FUN!

by pikpobedy
Replies
7
Views
1,449

### Always integrate. The area under the power usage...

Always integrate. The area under the power usage (y axis) versus time (x axis) curve is energy consumed.
The current and voltage must be measured in real time (sampling is fine), the measurements...
20. ## Thread: Under my arm (subtitle = the human antenna)

by pikpobedy
Replies
11
Views
1,573

### A well known phenomenom: Hold a remote control...

A well known phenomenom: Hold a remote control transmitter (garage door opener, car door opener, etc) against your head, it will lengthen the range noticeably. This is not a youtube hoax. The water...
21. ## Thread: Newton's Third Law and Collisions

by pikpobedy
Replies
25
Views
1,929

### Measurement of contact time in short duration...

Measurement of contact time in short duration sports ball impacts: an experimental method and correlation with the perceptions of elite golfers
22. ## Thread: Newton's Third Law and Collisions

by pikpobedy
Replies
25
Views
1,929

### As has been posted: The force is a function of...

As has been posted: The force is a function of the interaction. It is a result of how the materials interact. No interactions means no forces. A 5 m/s collision between two 1 kg balls made of brass,...
23. ## Thread: Newton's Third Law and Collisions

by pikpobedy
Replies
25
Views
1,929

I surmised your OP was well answered in the posts that said the momentum and KE are conserved in perfectly elastic collisions. The best and simplest way to understand...
24. ## Thread: modeling and simulation in physics

by pikpobedy
Replies
2
Views
1,389

### Why do you want to transfer to a better school? I...

Why do you want to transfer to a better school? I know the Swiss aviation manufacturing industry is not as developed as the American, Russian, British and French industries but the Swiss have the...
25. ## Thread: Newton's Third Law and Collisions

by pikpobedy
Replies
25
Views
1,929

### Take a look at this. Fascinating fun. Momentum,...

Take a look at this. Fascinating fun. Momentum, Magnets & Metal Balls - Sixty Symbols
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