Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
The law of conservation of energy is:
-- Energy can't be created or destroyed.
-- Energy can't just appear out of nowhere. If you suddenly have
more energy, then the 'extra' energy had to come from somewhere.
-- Energy can't just disappear. If you suddenly have less energy,
then the 'missing' energy had to go somewhere.
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There are also conservation laws for mass and electric charge.
They say exactly the same thing. Just write 'mass' or 'charge'
in the sentences up above, in place of the word 'energy'.
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And now I can tell you that the conservation laws for energy and mass
are actually one single law ... the conservation of mass/energy. That's
because we discovered about 100 years ago that mass can convert
into energy, and energy can convert into mass, and it's the total of BOTH
of them that gets conserved (can't be created or destroyed).
How much mass makes how much energy ?
The answer is E = m c² .
Answer: hello question b is incomplete attached below is the missing question
a) attached below
b) V = 0.336 ft/s
Explanation:
Elongation ( Xo) = 16/ 7 feet
mass attached to 4-foot spring = 16 pounds
medium has 9/2 times instanteous velocity
<u>a) Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 2 ft/s</u>
The motion is an underdamped motion because the value of β < Wo
Wo = 3.741 s^-1
attached below is a detailed solution of the question
The rule that is used to get the strength of magnetic field at the center of solenoid (B) is:
B = <span>µ x n x I where:
</span>µ is the permeability of the medium where the solenoid is based. In this problem, the medium is air which means that µ = <span>µ </span><span>o = 4 pi x 10^-7 Tm/A
</span>I is the current passing (I = 4 amperes)
n is the number of turns per unit length (5000 turns)
Substituting in the mentioned equation, we find that:
B = 4 x 3.14 x 10^-7 x 5000 x 4 = 25.132 mT
The best symbolizes the hydrogen bonding between two water molecules is given in the diagram.
<h3 /><h3>What is hydrogen bonding?</h3>
A hydrogen bond is an attraction between an electronegative atom carrying a single pair of electrons—the hydrogen bond acceptor—and a hydrogen atom that is covalently bonded to a more electronegative "donor" atom or group.
One definition of a polar covalent bond is one in which one atom has a stronger alternation for electron negativity difference between two bonds, the more polar the link.
Polar molecules like H2O have a mild partial negative charge in one area and a partial positive charge in another.
to learn more about hydrogen bond go to -
brainly.com/question/1426421
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