geek science tech

A phone battery has an energy equivalent to 40 .44 Magnum bullets

Now, that is something new, but the fact that a phone battery can hurt you is not new. Do NOT ever, under any circumstances breck the battery apart. Since it has compounds of lithium in it and since lithium is very reactive with air, the batter will start burning and will explode.

The energy stored in a battery is the same as the one from 40 .44 Magnum bullets. The word says that such a bullet can rip you head off, but closer to the truth would be that it will rip a part of you head off. The same with the battery: it can burn and hurt you if you are not careful enough. Also, try not to speak at the phone while the phone is charging.

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SciShow: what is energy?

Energy can be found everywhere and in many forms. In the same way as the existence of matter, energy as existed since the dawn of the Universe. It is a constant quantity in the Universe: nothing gets lost, but only transformed.

Energy is the ability to do work and mass and energy are the same thing. Remember E=mc^2? Energy can never be created, but only transferred. Also, it seems that we are 98% energy. Veritasium created a great video about mass that really needs to be watched: if mass is energy, it means that the trees are full of energy?

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[Rant] And again: our mass comes from the kinetic and potential energy inside nucleons

Yesterday you could read on this blog that mass and energy are the same, as mass is energy compressed in a given space in a given form. Nucleons, the subatomic particles that form the nucleus, ie the protons and neutrons, contain most of our mass and inside them there are quarks which are bound by the strong force into a “subatomic threesome”.

That strong force is, in fact, the kinetic energy and potential energy from within the nucleons, but the quarks amount only to a max of 2% of the atom’s total mass. Most of the mass is, therefore, coming from the energy that binds the quarks together. Smashing, ain’t it? Knowing that you’re pure freaking energy and that mass, as we knew it, doesn’t even exist. Cool, eh?

Now, let’s learn more about mass, inertial mass and why a hollow tube goes down a slope slower than a full, solid tube. Why? Because you need more energy to put that hollow tube into motion as all the mass is in the tube walls, not spread across the entire solid.

That would mean, in a sense that we all could better understand, that bicycle wheels should be made of solid materials, not the common wheel with all the weight distributed along the outside of the circle.

Check this out:

Also, given a inertial reference frame and a gravitational reference frame, mass and weight are interchangeable terms. Mass and weight are almost the same:

And, of course, you should not forget that weight is given by the gravitational force, which is NOT a force. In fact, gravity is a space-time distortion:

And of course, who the heck cares that we’re only 2% actual mass and 98% energy and that we, maybe, will be able to invent some anti-gravity ships sometimes in the future if we learn to harness anti-matter like real cowboys? No, really, who cares?

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What’s the difference between mass and energy?

Nick, from Science Asylum, explains the difference between mass and energy. There is none. Mass is energy compressed in a given space. Most of the weight of a subatomic particle in the nucleus comes from the nuclear strong forces inside the protons and neutrons, not from the particles themselves, like gluons or quarks.

Neat, eh? Remember E=mc^2? Also, check the video about the fact that it is not the Higgs Bosson that gives us mass:

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How big is the force that a falling bowling ball hits you with? [painfull]

Ask A mathematician explains in a joyful manner how much force is involved when a falling bowling ball hits your toes. As painful as it is we have to do a bit of math to see what energies are at work in there.

As you know Energy = Work = Force * Distance. Since the energy is conserved the energy of the falling ball needs to be equal to the energy of the ball that is stopped by your foot and thus: Ff * Df = Fs * Ds, the lowercase f means “fall” and s means “stop”.

What does the physicist say? This:

So, if you drop a 10 pound ball 4 feet (48 inches), and it stops in a quarter inch, then the force at the bottom of the fall is F = 48/0.2510lbs ~ 200lbs. This is why padding is so important; if that distance was only an eighth of an inch (seems reasonable) then the force jumps to 400lbs, and if that distance is increased to half an inch then the force drops to 100 lbs.

Science can be toe-crushingly fun :))

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Learn what energy is with Bill Nye, The Science Guy

Bill Nye, one fo the greatest educators of our times, explains in this old video what energy is. Many know that energy is conserved, that you can’t make or destroy energy, that is transforms and that ii is equal with the work done by a force that needs to move an object for a given distance.

But what is energy?

Energy is an abstract concept, a “thing” that is conserved, a mathematical way to track transformations and interactions. It is a numerical value that describes some phenomena.

You can also read what energy is here and also see some extra explanations int he video from below:


E=mc ² is not the complete equation

Man, you got to love Minute Physics. Being too lazy and accepting many formulae like they were laws, when they are only a part of the whole, leads us to ignorance. Minute Physics explainws why E=mc ² is only a partof Einstens equation. Awesome.

The full equation is E ²=(mc ²) ²+(pc) ². For an object that is not moving, thus p – momentum – being zero we get E=mc². If an object is moving then we get the full equation. Also, if an object is masless, like the photons, then you get their energy as being E=(pc).

Other sources:
Q: What does “E=mc2” mean?

Also, here is another explanation from Dr. Don, from Fermilab:

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Destin explains : Physics of Slingshots [video]

Destin (Smarter Every Day) does interesting things in his back yard, and that means that his videos are educational at heart and make you understand better the world we live in. He puts theory into practice and shows us the beauty of applied science.

Did you ever wondered how slingshots work? It seems that the secret is in the process of transforming kinetic energy into potential energy. Translated: use movement to push things around. Simple, not? Well, not really that simple, but Destin explains it in an easy way. Love it!