Answer:
C ) 1.53
Explanation:
The critical angle of a material is given by the formula

where
c is the critical angle
n is the refractive index
This formula is valid if the second medium is air (which is the case of the problem).
In this problem, we know the critical angle:

Therefore we can rearrange the equation to find the refractive index:

<span>The life forms of the biosphere are located within Earth's surface.</span>
(C)
Explanation:
The circle has a radius r = 0.5 m, which means that its circumference C is

One revolution means that the stopper travels a distance equal to the circumference of the circle so the velocity of the stopper is

Answer:
Impedance, Z = 107 ohms
Explanation:
It is given that,
Resistance, R = 100 ohms
Inductance, 
Capacitance, 
Frequency, f = 60 Hz
Voltage, V = 120 V
The impedance of the circuit is given by :
...........(1)
Where
is the capacitive reactance, 

is the inductive reactance, 

So, equation (1) becomes :

Z = 106.26 ohms
or
Z = 107 ohms
So, the impedance of the circuit is 107 ohms. Hence, this is the required solution.
Answer:
The law of conservation of momentum states that the total momentum of interacting objects does not <u>change</u>. This means the total momentum <u>before</u><u> </u>a collision or explosion is equal to the total momentum <u>after</u><u> </u>a collision or explosion.