Answer:
note:
<u>solution is attached in word form due to error in mathematical equation. furthermore i also attach Screenshot of solution in word due to different version of MS Office please find the attachment</u>
Near Greenland in the northern hemisphere <span />
Answer:
Only main sequence stars have a well-defined relationship between spectral type and luminosity.
Explanation:
Low-mass stars have much longer lifetimes than high-mass stars.
Answer:
A sound wave is called a longitudinal wave because compressions and rarefactions in the air produce it. The air particles vibrate parallel to the direction of propagation.
Answer:
The same as the escape velocity of asteorid A (50m/s)
Explanation:
The escape velocity is described as follows:

where
is the universal gravitational constant,
is the mass of the asteroid and
is the radius
and since the scape velocity is 50m/s:

Now, if the astroid B has twice mass and twice the radius, we have that tha mass is: 
and the radius is: 
inserting these values into the formula for escape velocity:

and we have found that
, so the two asteroids have the same escape velocity.
We found that the expression for escape velocity remains the same as for asteroid A, this because both quantities (radius and mass) doubled, so it does not affect the equation.
The answer is
Asteroid B would have an escape velocity the same as the escape velocity of asteroid A