Answer: 1.39 s
Explanation:
We can solve this problem with the following equations:
(1)
(2)
Where:
is the length the steel wire streches (taking into account 1mm=0.001 m)
is the length of the steel wire before being streched
is the force due gravity (the weight) acting on the pendulum with mass 
is the transversal area of the wire
is the Young modulus for steel
is the period of the pendulum
is the acceleration due gravity
Knowing this, let's begin by finding
:
(3)
Where
is the diameter of the wire
(4)
(5)
Knowing this area we can isolate
from (1):
(6)
And substitute
in (2):
(7)
(8)
Finally:

Heat from burning fuel warms the walls of the firebox section of the furnace in
A. a hot-water heating system.
B. a hot-air heating system.
C. a compressor compartment.
D. an evaporation system.
From the answers provided, I believe the possible answer would be the last option, silicon, oxygen, and one or more metals. Here's my reasoning: the most abundant mineral group found in the Earth's crust is the silicate group. The silicate materials contain both oxygen and silicon. Silicates are the most common minerals in the rock-formation process, and it has, in fact, been estimated that they make up 75 to 90 percent of the Earth's crust. From this piece of evidence, I can guess that the answer will possibly be D, silicon, oxygen, and one or more metals.
It should also be noted that the additional elements that combine with the silicon-oxygen tetrahedron are involved with the other elements commonly found in the Earth's crust and mantle. They are aluminum, calcium, iron, magnesium, potassium and sodium.
The answer is a matter of opinion, and you're going to get different answers
from different people. Here's <u>my</u> take on it:
The writers, producers and advertising sponsors of these shows certainly
don't think they're boring. And <em><u>definitely</u></em> neither do the TV networks that
decide which ones to broadcast.
I'm not trying to say "The experts don't think they're boring, so you must
be wrong". I'm trying to say that different people have different opinions
about the same shows, and in <em>your</em> case,<em> you</em> find them boring.
My conclusion is this:
I think you're finding TV shows boring nowadays because you're growing
as a person. You've grown, developed, and matured to the point where
you're above the level of audience that the shows are pitched for. That's
a very good thing !
You're sad because you used to get pleasure and entertainment from TV,
and now it doesn't give you those things. That's like losing an old friend,
that you used to have such fun playing with, but he just doesn't do it for
you any more.
Now that you've grown up, you've made new friends. With them, you do
things that you wouldn't even understand with your younger friends. And
you develop new interests, like ... I don't know ... books, movies, hobbies,
your church, your profession, learning new things, developing new skills,
exercising your brain, writing, volunteer work, ham radio, building fine
furniture, singing, learning to write music, raising tropical plants, sculpture,
politics ... whatever turns you on. Some people never grow past the stage
where staring at the tube is all they need in life, because they don't have
what it takes to be interested in anything else. Those are the people that
TV is aimed at. But you have more, and that's why TV isn't enough for you.
There are other possible reasons why TV bores you. But until I know more
about you, I think it's a very, very good sign.