Answer:
26.6°
Explanation:
refractive index of diamond, n = 2.23
When a ray of light passes from denser medium to the rarer medium and refracts at an angle of 90 degree from the normal of the surface, such angle of incidence in the denser medium is called the critical angle.
By the Snell's law
For critical angle, angle of incidence is critical angle, i = θc and angle of refraction, r = 90
So,
Sin θc / Sin 90 = 1 / 2.23
Sin θc = 0.448
θc = 26.6°
Thus, the critical angle is 26.6°.
Answer:
The distance between the lighthouse and the ship
from the start position A = 5.08 miles
from the Final point B = 7.23 miles
Explanation:
Note: Refer the figure
Let the position of the lighthouse be 'L'
Given:
When the ship is at the position A, ∠DAL=37°
Now, when the ship sails through a distance of 2.5 i.e at position B
mathematically,
AB=2.5 miles
∠ABL=25°
Now,
∠DAL + ∠LAB = 180°
or
37° + ∠LAB = 180°
or
∠LAB = 180° - 37° = 143°
Also, In ΔLAB
∠LAB + ∠ABL + ∠ALB = 180°
or
143° + 25° + ∠ALB = 180°
or
∠ALB = 180° - 143° - 25° = 12°
Now using the concept of the sin law
In ΔLAB
or
AL = 5.08 miles
and,
or
BL = 7.23 miles
hence,
The distance between the lighthouse and the ship
from the start position A = 5.08 miles
from the Final point B = 7.23 miles
