If a beam passes from a material with a refractive index of 1.3 into a material with a refractive index of 1.7 at an angle of 25 degrees (from normal), what is the angle of refraction of the beam? is the beam bent towards normal or away from it? sketch a diagram of this problem with rays, angles, and the interface labeled.

18.86° , it will bend towards normal.

Explanation:

For refraction,

Using Snell's law as:

Where,  

 is the angle of incidence  ( 25.0° )

is the angle of refraction  ( ? )

is the refractive index of the refraction medium  (n=1.7)

is the refractive index of the incidence medium ( n=1.3)

Hence,  

Angle of refraction = = 18.86°

Since, the light ray is travelling from a material with a refractive index of 1.3 into a material with a refractive index of 1.7 or lighter to denser medium, it will bend towards normal.

The diagram is shown below:

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min