Answer:
16.8ohms
Explanation:
According to ohm's law which states that the current passing through a metallic conductor at constant temperature is directly proportional to the potential difference across its ends.
Mathematically, V = IRt where;
V is the voltage across the circuit
I is the current
R is the effective resistance
For a series connected circuit, same current but different voltage flows through the resistors.
If the initial current in a circuit is 19.3A,
V = 19.3R... (1)
When additional resistance of 7.4-Ω is added and current drops to 13.4A, our voltage in the circuit becomes;
V = 13.4(7.4+R)... (2)
Note that the initial resistance is added to the additional resistance because they are connected in series.
Equating the two value of the voltages i.e equation 1 and 2 to get the resistance in the original circuit we will have;
19.3R = 13.4(7.4+R)
19.3R = 99.16+13.4R
19.3R-13.4R = 99.16
5.9R = 99.16
R= 99.16/5.9
R = 16.8ohms
The resistance in the original circuit will be 16.8ohms
There's a very subtle thing going on here, one that could blow your mind.
Wherever we look in the universe, no matter what direction we look,
we see the light from distant galaxies arriving at our telescopes with
longer wavelengths than the light SHOULD have.
The only way we know of right now that can cause light waves to get
longer after they leave the source is motion of the source away from
the observer. The lengthening of the waves on account of that motion
is called the Doppler effect. (The answer to the question is choice-c.)
But that may not be the only way that light waves can get stretched. It's
the only way we know of so far, and so we say that the distant galaxies
are all moving away from us.
From that, we say the whole universe is expanding, and that right there is
one of the strongest observations that we explain with the Big Bang theory
of creation.
Now: If ... say tomorrow ... a competent Physicist discovers another way
for light waves to get stretched after they leave the source, then the whole
"expanding universe" idea is out the window, and probably the Big Bang
theory along with it !
Now that our mind has been blown, come back down to Earth with me,
and I'll give you something else to think about:
It's true that when we look at distant galaxies, we do see their light
arriving in our telescopes with longer wavelengths than it should have.
And then we use the Doppler effect to calculate how fast that galaxy
is moving away from us. That's all true. Astronomers are doing it
every day. I mean every night.
So here's the question for you to think about ... maybe even READ about:
When the light from a distant galaxy pours into our telescope, and we
look at it, and we measure its wavelength, and we find that the wavelength
is longer than it should be ... how do we know what it should be ? ? ?
Explanation:
Given:
v₀ = 0 m/s
a = 2.50 m/s²
t = 4 s
Find: v
v = at + v₀
v = (2.50 m/s²) (4 s) + 0 m/s
v = 10 m/s
B verifying is the answer
A) It is very dry at the equator because it is so hot.
False. It depends on what else is around.
The Sahara Desert is near the Equator.
But so is the Amazon rain forest.
B) Higher places are usually warmer because they are closer to the Sun.
False. Higher places are usually colder, because the air is thinner.
C) Land masses change the direction of currents.
True
D)The sun provides energy needed for the evaporation process. Gravity allows water droplets to fall as precipitation.
True
