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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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Which property is unique to electromagnetic waves?(1 point)
olya-2409 [2.1K]

Answer:

They can travel in a vacuum.

Explanation:

» Only electromagnetic waves travel through vacuum. The other mechanical waves require a material medium to travel.

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4 0
2 years ago
Read 2 more answers
What layer of the atmosphere is made mostly of hydrogen and helium?
ikadub [295]
On Earth, none of the atmosphere is.
6 0
2 years ago
Why are there two fluoride ions in magnesium fluoride but only one fluoride ion in lithium fluoride
postnew [5]
This would be more of a chemistry question. Remember magnesium has a charge of 2+, and would need to hand off its two extra electrons. Fluorine can only take one electron at a time, so there needs to be two fluorines to take one magnesium's 2 electrons. 

With lithium, it has a +1 charge, so it has one extra electron, which it can hand off to just 1 fluorine atom. 

Another way of looking at this is: Mg^{2+} + 2F^{-} = MgF2  (the charges must balance out to zero)

Li^{+} + F^{-} = LiF (the charges balance out to zero)
5 0
3 years ago
Read 2 more answers
How many minutes would it take a light wave to travel from the planet Venus to Earth? (Average distance from Venus to Earth = 28
Gnesinka [82]

Answer:

t=2.51min

Explanation:

The time taken by the light to travel a given distance is defined as:

t=\frac{d}{c}

Here c is obviously the speed of light. Now we convert the average distance form Venus to Earth to meters:

28*10^{6}mi*\frac{1609.34}{1mi}=4.51*10^{10}m

Finally, we calculate the minutes taken by the light to travel from Venus to Earth:

t=\frac{4.51*10^{10}m}{3*10^8\frac{m}{s}}\\t=150.33s*\frac{1min}{60s}=2.51min

6 0
3 years ago
How do particles move differently in transverse waves and in surface water waves?
elixir [45]
The particles always move parallel and perpendicular to the waves. The waves which are in the water moves a circle. Both up and down and back and forth.

Good luck :)
3 0
3 years ago
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