The angle of prism is 41.81 degrees.
<u>Explanation:</u>
For no emergence to be taken place, inside a prism, Total Internal Reflection (TIR) should take place at the second surface. For TIR, at second surface, angle of refraction must be greater than critical angle. Angle of prism is related to refraction as,

Since,
= C and 
This implies 



when sin goes to other side become as sin inverse of value, and obtain the result as below,

Answer:
Part a) 
Part b) 
Explanation:
Part a) what is its frequency, in rev/s
we have that
An old-fashioned LP record rotates at 33 1/3 RPM
so

Convert mixed number to an improper fraction

Remember that

Convert rev/min to rev/sec

Simplify

Part b) what is it period, in seconds
we know that
The period is the reciprocal of the frequency
therefore
the frequency is

Answer:
Cycles per second is dependent on the construction of the alternator and the 120 volts is dependent upon the current and resistance in the circuit according to the ohms law.
Explanation:
We are given with AC of 120 volts, 20 amperes and 60 hertz frequency.
<u>According to the Ohm's law, we find its resistance:</u>



So, this 6 ohm resistance controls the current controls the magnitude of the AC current, while the frequency of the current remains constant and depends upon the construction and rotational speed of the armature of the alternator producing the current.
Here the value of frequency is the number of times the current changes its direction or the polarity in one second.