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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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Is the force of gravity that attracts my body to the Earth related to the force of gravity between the planets and the Sun
pochemuha

Certainly gravity is a force that exists between the Earth and the objects that are near it. As you stand upon the Earth, you experience this force.

8 0
2 years ago
What happens to hydrogen in the core of stars
mezya [45]
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6 0
3 years ago
Describe two methods that can be used to cook eggs.​
weeeeeb [17]
You can poach an egg which enfolded boiling water and stirring it and dropping a cracked egg in the water until it is fully cooked or you could hard boil and egg by boiling water and letting it cook 5,6 minutes tell you have a soft yellow center or which ever way you prefer
4 0
2 years ago
Which is a true statement regarding the law of mass balance? A.Solids, gases, and liquids have their own specific equations for
nata0808 [166]

Answer:

b. when the body converts a nutrient  to another substance, there  is no effect on mass balance.

Explanation:

The law of mass balance states that the mass stays the same in any chemical reaction, that is the reason why a nutrient in human body transforms to another substance like another substance, into muscles (that has mass), a body fluid ( that has mass) or another substance, but the total mass will keep the same, just in a different shape, nature or state.

6 0
3 years ago
ou have designed and constructed a solenoid to produce a magnetic field equal in magnitude to that of the Earth (5.0 10-5 T). If
Nikitich [7]

Answer:

I = 0.0256 A

Explanation:

Given,

Magnetic field, B = 5 x 10⁻⁵ T

Number of turns, N = 450

length = 29 cm

Current,I = ?

Using formula of magnetic field due to solenoid

B = \mu_0 NI

I = \dfrac{B}{\mu_0N}

I = \dfrac{5\times 10^{-5}\times 0.29}{450\times 4\pi \times 10^{-7}}

I = 0.0256 A

Hence, the current obtained is equal to 0.0256 A.

5 0
3 years ago
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