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LenaWriter [7]
2 years ago
9

Dish-shaped reflectors are used to steer microwaves in order to establish communications links between nearby buildings. Those r

eflectors are often made from metal mesh. Why don't they have to be made from solid metal sheets
Physics
1 answer:
Ad libitum [116K]2 years ago
5 0

A "screen" or even just a set of parallel bars are highly reflective to electromagnetic waves as long as the open spaces are small compared to the wavelengths.

"Grid" dishes work fine ... with less weight and less wind resistance ... for frequencies below about 3 GHz. (Wavelengths of at least 10 cm.)

(I even worked on a microwave system in South America where huge grid dishes were used on a 90-mile link.)

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Planets A and B have the same mass, but planet A is half the size of planet B.
pychu [463]

Answer:

c. You would weigh less on planet A because the distance between

you and the planet's center of gravity would be smaller.

Explanation:

The statement that best describes your weight on each planet is that you would weigh less on planet A because the distance between you and the planet's center of gravity would be smaller.

  • This is based on Newton's law of universal gravitation which states that "the force of gravity between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distances between them".

Since weight is dependent on the force of gravity and mass, the planet with more gravitational pull will have masses on them weighing more.

  • Since the distance between the person and the center of the planet is smaller, therefore, the weight will be lesser.
7 0
3 years ago
Read 2 more answers
Which picture represents 2NO2?
wariber [46]
2NO2 means that there is 2 oxygen atoms and one nitrogen with two sets of that. So its the third one

3 0
3 years ago
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If I were to transmit a radio wave in our three dimensional world could a fourth dimensional “being” be able to receive it?
Morgarella [4.7K]
Depends. Are you talking about a mathematical 4th dimension (in which there is infinite dimensions) or some sort of etheral dimension (in which there is no scientific evidence for)

If you mean the first then yes. But it depends how these beings exist. From our understanding we only can theorize shapes in 4-d and if we assume that there is only one universe these "beings" arleady exist and thus any message in 3-d would be sent to them like a shadow ("flat").
If they exist in a alternate "plane" then you would need some method to transverse this plan and if u did, then we would easily be able to communicate, but we would at first sound like a wild animal. They either would ignore us, not understand or perceive us, or they would attempt to send back a signal (essential they are ET's)

IF you mean the second then thats some mystic stuff and its pretty creepy (although a fun read for me :P)
 
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5 0
3 years ago
Density is given in ____.<br> a. Pa/cm3<br> c. g/s2<br> b. N/m2<br> d. g/cm3
Ainat [17]
Density is defined as  [mass] / [volume] .

The only choice listed with those physical dimensions is 'd' .
3 0
3 years ago
If 230 W of power is produced in 10 seconds, how much work is done?
liq [111]

Answer:

Hello There!!

Explanation:

Use this equation:Work done = Force x Distance.

Work done=230W×10s

Work done=2300J

hope this helps,have a great day!!

~Pinky~

7 0
2 years ago
Read 2 more answers
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