Idk can u say it in a another way
Answer:Simple Covalent substance
Explanation:Simple covalent substance describes a substance that has a low melting point and poor electrical conductivity because:
(1)melting point :For the covalent bond and intermolecular force that are present in a simple covalent substance,energy is needed to break the forces of attraction present. In the simple covalent substance, little energy is needed because the intermolecular forces present are broken because they are weaker compared to the covalent bond present.
Therefore, when simple covalent substance melts,only the intermolecular forces are broken leaving only the covalent bond in the substance.
(2) poor conductivity: for a substance to conduct electricity,it must have charged particles which are free to move to and fro.
But in the simple covalent substance,there are no charged particles that can be separated due to the covalent bond present in simple covalent substance.
Answer:

Explanation:
Information we have:
velocities:
initial velocity:
(starts from rest)
final velocity: 
time:
Since we need the answer in
, we nees to convert the speed to meters per second:

We find the acceleration with the following formula:

substituting the known values:

the acceleration is 10.07
The acceleration due to gravity serves as the centripetal acceleration of the objects that orbits the Earth. The centripetal acceleration due to gravity is calculated through the equation,
a = v²/r
where v is the speed and r is the radius. Substituting the known values to the equation,
9.8 m/s² = (420 m/s)² / r
The value of r from the equation is 18000 m or equal to 18 km.
<em>Answer: 18 km</em>
Complete Question
Due to blurring caused by atmospheric distortion, the best resolution that can be obtained by a normal, earth-based, visible-light telescope is about 0.3 arcsecond (there are 60 arcminutes in a degree and 60 arcseconds in an arcminute).Using Rayleigh's criterion, calculate the diameter of an earth-based telescope that gives this resolution with 700 nm light
Answer:
The diameter is
Explanation:
From the question we are told that
The best resolution is 
The wavelength is 
Generally the
1 arcminute = > 60 arcseconds
=> x arcminute => 0.3 arcsecond
So

=> 
Now
60 arcminutes => 1 degree
0.005 arcminutes = > z degrees
=> 
=> 
Converting to radian

Generally the resolution is mathematically represented as

=> 
=>
=>