Answer:
they were slaves, so they did practically everything anyone didn't do.
Explanation:
btw, which war? or battle?
Answer:
Because the light reflects multiple times until it gets to the Cassegrain focus.
Explanation:
The Cassegrain design can be seen in a reflecting telescope. In this type of design the light is collected by a concave mirror, and then intercepted by a secondary convex mirror, and sends it down to a central opening in the primary mirror (concave mirror), in which a detector is placed (Cassegrain focus)
Since, the light is reflected many times due to Cassegrain design, that leads to shorter telescopes.
Answer:
The boiling point temperature of this substance when its pressure is 60 psia is 480.275 R
Explanation:
Given the data in the question;
Using the Clapeyron equation


where
is the change in enthalpy of saturated vapor to saturated liquid ( 250 Btu
T is the temperature ( 15 + 460 )R
m is the mass of water ( 0.5 Ibm )
is specific volume ( 1.5 ft³ )
we substitute
/
272.98 Ibf-ft²/R
Now,

where P₁ is the initial pressure ( 50 psia )
P₂ is the final pressure ( 60 psia )
T₁ is the initial temperature ( 15 + 460 )R
T₂ is the final temperature = ?
we substitute;


480.275 R
Therefore, boiling point temperature of this substance when its pressure is 60 psia is 480.275 R
The relationship between frequency and wavelength for an electromagnetic wave is

where
f is the frequency

is the wavelength

is the speed of light.
For the light in our problem, the frequency is

, so its wavelength is (re-arranging the previous formula)