Answer: 
Explanation:
Density is a characteristic property bodies and materials, and is defined as the relationship between the mass
and the volume
, as shown below:
(1)
In the case of the neutron star, we know it has the same mass as the Sun:

And its radius is 
On the other hand, if we assume this neutron star has a spherical shape, its volume can be calculated by the following formula:
(2)
(3)
(4)
Substituting (4) in (1):
(5)
Finally:
I hope my answer helped u under stand better
Answer:
The displacement of the train in this time period is 2,616.86 m.
Explanation:
A Uniformly Varied Rectilinear Motion is Rectilinear because the mobile moves in a straight line, Uniformly because of there is a magnitude that remains constant (in this case the acceleration) and Varied because the speed varies, the final speed being different from the initial one.
In other words, a motion is uniformly varied rectilinear when the trajectory of the mobile is a straight line and its speed varies the same amount in each unit of time (the speed is constant and the acceleration is variable).
An independent equation of useful time in this type of movement is:
<em>Expression A</em>
where:
- vf = final velocity
- vi = initial velocity
- a = acceleration
- d = distance
The equation of velocity as a function of time in this type of movement is:
vf=vi + a*t
So the velocity can be calculated as: 
In this case:
- vf=42.4 m/s
- vi=27.5 m/s
- t=75 s
Replacing in the definition of acceleration: 
a=0.199 m/s²
Now, replacing in expression A:

Solving:

d= 2,616.86 m
<u><em>The displacement of the train in this time period is 2,616.86 m.</em></u>
Oxidation number for Xenon is XeOF2 and Argon is 0.