Answer:
m = 469.51
Explanation:
Given that,
The diameter of a refracting telescope is 1.48 m
Focal length of the objective lens is 15.4 m
Focal length of an eyepiece is 3.28 cm
We need to find the angular magnification of the telescope. The ratio of focal length of objective lens to the focal length of the eye piece is called angular magnification of the telescope. So,

So, the angular magnification of the telescope is 469.51.
Answer:
The number of vacancies per cubic meter is 1.18 X 10²⁴ m⁻³
Explanation:
![N_v = N*e[^{-\frac{Q_v}{KT}}] = \frac{N_A*\rho _F_e}{A_F_e}e[^-\frac{Q_v}{KT}}]](https://tex.z-dn.net/?f=N_v%20%3D%20N%2Ae%5B%5E%7B-%5Cfrac%7BQ_v%7D%7BKT%7D%7D%5D%20%3D%20%5Cfrac%7BN_A%2A%5Crho%20_F_e%7D%7BA_F_e%7De%5B%5E-%5Cfrac%7BQ_v%7D%7BKT%7D%7D%5D)
where;
N
is the number of atoms in iron = 6.022 X 10²³ atoms/mol
ρFe is the density of iron = 7.65 g/cm3
AFe is the atomic weight of iron = 55.85 g/mol
Qv is the energy vacancy formation = 1.08 eV/atom
K is Boltzmann constant = 8.62 X 10⁻⁶ k⁻¹
T is the temperature = 850 °C = 1123 k
Substituting these values in the above equation, gives
![N_v = \frac{6.022 X 10^{23}*7.65}{55.85}e[^-\frac{1.08}{8.62 X10^{-5}*1123}}]\\\\N_v = 8.2486X10^{22}*e^{(-11.1567)}\\\\N_v = 8.2486X10^{22}*1.4279 X 10^{-5}\\\\N_v = 1.18 X 10^{18}cm^{-3} = 1.18 X 10^{24}m^{-3}](https://tex.z-dn.net/?f=N_v%20%3D%20%5Cfrac%7B6.022%20X%2010%5E%7B23%7D%2A7.65%7D%7B55.85%7De%5B%5E-%5Cfrac%7B1.08%7D%7B8.62%20X10%5E%7B-5%7D%2A1123%7D%7D%5D%5C%5C%5C%5CN_v%20%3D%208.2486X10%5E%7B22%7D%2Ae%5E%7B%28-11.1567%29%7D%5C%5C%5C%5CN_v%20%3D%208.2486X10%5E%7B22%7D%2A1.4279%20X%2010%5E%7B-5%7D%5C%5C%5C%5CN_v%20%3D%201.18%20X%2010%5E%7B18%7Dcm%5E%7B-3%7D%20%3D%201.18%20X%2010%5E%7B24%7Dm%5E%7B-3%7D)
Therefore, the number of vacancies per cubic meter is 1.18 X 10²⁴ m⁻³
Answer:
300 nm
Explanation:
R = Gas constant = 8.314 J/molK
r = Atomic radii = 
d = Atomic diameter = 
At STP
T = Temperature = 273.15 K
P = Pressure = 100 kPa
= Avogadro's number = 
The mean free path is given by

The answer that best represents the mean free path for gas molecules is 300 nm
Answer:
f = 55mm, h ’= -9.89 cm
f = 200 mm, h ’= 42.5 cm
Explanation:
For this exercise let's start by finding the distance to the image, using the equation of the constructor

where f is the focal length, p and q are the distances to the object and image, respectively
lens with f₁ = 55mm = 0.55cm
=
= 1.718
q₁ = 0.582 m
lens with f₂ = 200mm = 2m
=
= 0.4
q₂ = 2.5 m
the magnification of a lens is given by
m =
h ’=
let's calculate for each lens
f = 55mm
h '= - 0.582 / 10 1.7
h ’= 0.0989 m
h ’= -9.89 cm
f = 200 mm
h '= - 2.5 / 10 1.7
h ’= -0.425 m
h ’= 42.5 cm
The negative sign indicates that the image is real and inverted
The sum of angles in a regular pentagon is
180*(5 - 2) = 540°
Each internal angle is 540/5 = 108°.
Each vertex creates a line of symmetry to the midpoint of the opposite side,
as shown in the figure.
Answer: 5 lines of symmetry.