The easiest way to build a unit for energy is to remember that
'work' is energy, and
Work = (force) x (distance).
So energy is (unit of force) x (unit of distance)
[Energy] = (Newton) (meter) .
'Newton' itself is a combination of base units, so
energy is really
(kilogram-meter/sec²) (meter)
= kilogram-meter² / sec² .
That unit is so complicated that it's been given a special,
shorter name:
Joule .
It doesn't matter what kind of energy you're talking about.
Kinetic, potential, nuclear, electromagnetic, food, chemical,
muscle, wind, solar, steam ... they all boil down to Joules.
And if you generate, use, transfer, or consume 1 Joule of
energy every second, then we say that the 'power' is '1 watt'.
Answer:
Option (B) is correct.
Explanation:
Given that the molecules of hydrogen gas (
) react with molecules of oxygen gas (
) in a sealed reaction chamber to produce water (
).
The governing equation for the reaction is

From the given, the only fact that can be observed that 2 moles of
and 1 mole of
reacts to produce 2 moles of
.
As the mass of 1 mole of
grams ... (i)
The mass of 1 mole of
grams ...(ii)
The mass of 1 mole of
grams (iii)
Now, the mass of the reactant = Mass of 2 moles of
+ mass 1 mole of 
[ using equations (i) and (ii)]
grams.
Mass of the product = Mass of 2 moles of 
[ using equations (iii)]
=36 grams
As the mass of reactants = mass of the product.
So, mass is conserved.
Hence, option (B) is correct.
Answer:
B. 
Explanation:
Assuming we are dealing with a perfect gas, we should use the perfect gas equation:

With T the temperature, V the volume, P the pressure, R the perfect gas constant and n the number of mol, we are going to use the subscripts i for the initial state when the gas has 20 cubic inches of volume and absolute pressure of 5 psi, and final state when the gas reaches 10 psi, so we have two equations:
(1)
(2)
Assuming the temperature and the number of moles remain constant (number of moles remain constant if we don't have a leak of gas) we should equate equations (1) and (2) because
,
and R is an universal constant:
, solving for 


For the majority of instruments f = n f0 where f is the resonating frequency, n is any whole number and f0 is the fundamental.
<span>This applies to trumpets, violins, flutes and a broad range. </span>
<span>In such a </span>case<span> the first harmonic would be at n=1 and the second harmonic would be at n=2 </span>
<span>which gives a frequency of 84 Hz</span>
Parfocal is the term used to describe a microscope that maintains focus when the objective lenses are replaced.
<h3>
What is the name of the objective lens ?</h3>
For observing minute features within a specimen sample, a high-powered objective lens, often known as a "high dry" lens, is perfect. You can see a very detailed image of the specimen on your slide thanks to the 400x total magnification that a high-power objective lens and a 10x eyepiece provide.
The four objective lenses on your microscope are for scanning (4x), low (10x), high (40x), and oil immersion (100x).
The first-stage lens used to create a picture from electrons leaving the specimen is referred to as the "objective lens." The objective lens is the most crucial component of the imaging system since the quality of the images is determined by how well it performs (resolution, contrast, etc.,).
To learn more than objective lens , visit
brainly.com/question/17307577
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