Answer:
is reflected back into the region of higher index
Explanation:
Total internal reflection is a phenomenon that occurs when all the light passing from a region of higher index of refraction to a region of lower index is reflected back into the region of higher index.
According to Snell's law, refraction of ligth is described by the equation

where
n1 is the refractive index of the first medium
n2 is the refractive index of the second medium
is the angle of incidence (in the first medium)
is the angle of refraction (in the second medium)
Let's now consider a situation in which

so light is moving from a medium with higher index to a medium with lower index. We can re-write the equation as

Where
is a number greater than 1. This means that above a certain value of the angle of incidence
, the term on the right can become greater than 1. So this would mean

But this is not possible (the sine cannot be larger than 1), so no refraction occurs in this case, and all the light is reflected back into the initial medium (total internal reflection). The value of the angle of incidence above which this phenomen occurs is called critical angle, and it is given by

Answer:
-6.49 m/s
Explanation:
This is doppler effect.
The equation is;
F_l = [(v + v_l)/(v + v_s)]F_s
Where;
F_l is frequency observed by the listener
v is speed of sound
v_l is speed of listener
v_s is speed of source of the sound
F_s is frequency of the source of the sound
In this question, the source of the sound is the moving vehicle.
Thus;
F_l = F_beat + F_s
We are given beat frequency (f_beat) as 5 Hz while source frequency (F_s) as 260 Hz.
So,
F_l = 5 + 260
F_l = 265 Hz
Since listener is sitting by car, thus; v_l = 0 m/s
Thus,from our doppler effect equation, let's make v_s the subject;
v_s = F_s[(v + v_l)/F_l] - v
Speed of sound has a value of v = 344 m/s
Thus;
v_s = 260[(344 + 0)/265] - 344
v_s = -6.49 m/s
This value is negative because the source is moving towards the listener
Answer:
if no mistaken then it is 300kN
Explanation:
Using SI units (the default if a system is not specified) 200T = 200000kg as the mass of the whale, it would weigh 1960kN in 1g Earth gravity.
On the Moon, the acceleration is 0.166g, to it would weigh about 330kN.
Answer:
a) 245 N
b) 392 J
c) 196 W
Explanation:
a) Force needed to lift the 25 kg object is the same as the weight of the object:

b) Work is the force exerted times the distance moved:

c) The power exerted is the quotient of the work done over the amount of time it took to move the object: