Answer:
λ = 0.0167 m = 16.7 mm
Explanation:
The wavelength of these radio waves can be found out by using the formula for the speed of radio waves:
v = fλ
where,
v = speed of radio waves = speed of light = 3 x 10⁸ m/s
f = frequency of radio waves = 18 GHz = 18 x 10⁹ Hz
λ = Wavelength = ?
Therefore,
3 x 10⁸ m/s = (18 x 10⁹ Hz)λ
λ = (3 x 10⁸ m/s)/(18 x 10⁹ Hz)
λ = 0.0167 m = 16.7 mm
B
It changes direction when it passes through an opening
С
It changes its speed and wavelength when it passes through an opening
D
It changes direction when it passes from one medium to another
E
It changes its speed and wavelength from one medium to another.
F
It changes direction when it bounces off of a solid surface.
If a sound wave refracts,It changes its speed and wavelength when it bounces off of a solid surface,It changes its speed and wavelength when it passes through an opening, and It changes direction when it passes from one medium to another. Therefore, option A, C and D are correct.
An important case in which sound waves change form or spread out is called refraction. This phenomenon affects the bending of a sound wave owing to changes in the wave's speed.
Refraction is the reason ocean waves near a shore parallel to the beach and why glass lenses can be used to focus light waves.
If the air above the earth is warmed than that at the surface, sound will be change shape back downward toward the surface by refraction. Soundpropagates in all directions from a point source.
Thus, option A, C and D are correct.
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The ability to be drawn into thin sheet is called malleability. The ability to be drawn into thin wires is called ductility. Copper have a high melting point due to metallic bonding.
Metallic bonding is a type of chemical bonding that rises from the electrostatic attractive force between conduction electrons and positively charged metal ions. Metallic bonds are more more strong than covalent bond and ionic bond
Metallic bonds is between metals and metals, have the malleable and ductile property. Elements which have metallic bonding have high melting and boiling point. Since copper is a metal, it form strong metallic bond with itself. So, copper have a high melting point.
Therefore, copper have a high melting point due to metallic bonding.
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Answer:
Explanation:
H⁺ = 1.2 x 10⁻²
pH = - log[H⁺]
= - log [ 1.2 x 10⁻²]
= - log1.2 + 2
= - .079 + 2
= 1.921 .
B. Jupiter
C. Mars
D. Neptune
Answer: Jupiter is believed to have prevented the asteroids in the asteroid belt from forming a planet.