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3 years ago

Imagine a box sitting on a shelf. What forces are acting on the box?

1 answer:

3 0

In case of an object sitting at rest on another base, there are two equal and opposite forces – Normal force and the gravity.

Answer: Option A

Explanation:

When an object is placed at rest position on another object, there is a force exerted by the surfaces of the two contact objects. This force is denoted as Normal Force.

When an object such as a box is placed on a shelf, its surface exerts a contact force on the base of the shelf- The Normal force directed upward. Meanwhile, the gravity stays at its action and tries to pull the box towards itself.

Both of these forces however are equal and opposite and therefore, there is zero net force on the box. That's why it remains at rest, holding on Newton's third law.

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Why are TV shows nowadays so boring?

Anna [14]

The answer is a matter of opinion, and you're going to get different answers
from different people. Here's my take on it:

The writers, producers and advertising sponsors of these shows certainly
don't think they're boring. And definitely 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 your case, you 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.

3 0

2 years ago

Read 2 more answers

What is energy that comes from the movement of particles

e-lub [12.9K]

Thermal energy comes from the ,movement of particles which produces heat, the faster the movement is the more heat

5 0

2 years ago

Hydrogen is the second most abundant gas in the atmosphere? True or false?

Alenkinab [10]

False as oxygen is the second most abundant and nitrogen is the most abundant at 78%.

7 0

2 years ago

What is the action force of a flying bird?

kirill [66]

It is called the reaction force of a bird flying.

7 0

3 years ago

A ball is thrown horizontally from the top of a 60 m building and lands 100 m from the base of the building. How long is the bal

zhannawk [14.2K]

Answer:

The ball is in the air for 3.5 seconds

The initial horizontal component of velocity is 28.6 m/s

The vertical component of the final velocity is 34.3 m/s downward

The final velocity is 44.7 m/s in the direction 50.2° below the horizontal

Explanation:

A ball is thrown horizontally

That means the vertical component of the initial velocity $u_{y}=0$

The initial velocity is the horizontal component $u_{x}$

The ball is thrown from the top of a 60 m

That means the vertical displacement component y = 60 m

→ y = $u_{y}$ t + $\frac{1}{2}$ gt²

where g is the acceleration of gravity and t is the time

y = -60 m , g = -9.8 m/s² , $u_{y}=0$

Substitute these values in the rule

→ -60 = 0 + $\frac{1}{2}$ (-9.8)t²

→ -60 = -4.9t²

Divide both sides by -4.9

→ 12.2449 = t²

Take √ for both sides

∴ t = 3.5 seconds

* The ball is in the air for 3.5 seconds 

The initial velocity is the horizontal component $u_{x}$

The ball lands 100 meter from the base of the building

That means the horizontal displacement x = 100 m

→ x = $u_{x}$ t

→ t = 3.5 s , x = 100 m

Substitute these values in the rule

→ 100 = $u_{x}$ (3.5)

Divide both sides by 3.5

→ $u_{x}$ = 28.57 m/s

The initial horizontal component of velocity is 28.6 m/s

The vertical component of the final velocity is $v_{y}$

→ $v_{y}$ = $u_{y}$ + gt

→ $u_{y}$ = 0 , g = -9.8 m/s² , t = 3.5 s

Substitute these values in the rule

→ $v_{y}$ = 0 + (-9.8)(3.5)

→ $v_{y}$ = -34.3 m/s

The vertical component of the final velocity is 34.3 m/s downward

The final velocity v is the resultant vector of $v_{x}$ and $v_{y}$

→ Its magnetude is $v=\sqrt{(v_{x})^{2}+(v_{y})^{2}}$

→ Its direction $tan^{-1}\frac{v_{y}}{v_{x}}$

→ $v_{y}$ = 28.6 , $v_{y}$ = -34.3

Substitute this values in the rules above

→ $v=\sqrt{(28.6)^{2}+(-34.3)^{2}}=44.66$

→ Its direction $tan^{-1}\frac{-34.3}{28.6}=-50.18$

The negative sign means the direction is below the horizontal

The final velocity is 44.7 m/s in the direction 50.2° below the horizontal

7 0

2 years ago