Light is incident upin a piece of crown glass at an angle of 45°.whatis the angle of refraction?
2)a ray of light passes from air into water at an angle of 30°.find the angle of refraction
3) the speed of light in a plastic is 2.00×10mls.theindexof refraction of the plastic
To find the angle of refraction in different scenarios, we can use Snell's law, which relates the angles of incidence and refraction to the refractive indices of the two media involved.
1) Given that light is incident upon a piece of crown glass at an angle of 45°, we can find the angle of refraction using Snell's law. The refractive index of crown glass is approximately 1.52. Snell's law states:
n1 * sin(i) = n2 * sin(r),
where n1 and n2 are the refractive indices of the two media and i and r are the angles of incidence and refraction, respectively.
Plugging in the values, we have:
1 * sin(45°) = 1.52 * sin(r).
Rearranging the equation and solving for r:
sin(r) = (1 * sin(45°)) / 1.52
sin(r) = sin(45°) / 1.52
Taking the inverse sine of both sides:
r = arcsin(sin(45°) / 1.52)
r ≈ 29.1°
Therefore, the angle of refraction in crown glass is approximately 29.1°.
2) Similarly, if light passes from air into water at an angle of 30°, we can use Snell's law. The refractive index of air is approximately 1 and the refractive index of water is approximately 1.33.
Using Snell's law:
1 * sin(30°) = 1.33 * sin(r)
Rearranging the equation and solving for r:
sin(r) = (1 * sin(30°)) / 1.33
sin(r) = sin(30°) / 1.33
Taking the inverse sine of both sides:
r = arcsin(sin(30°) / 1.33)
r ≈ 22.5°
Therefore, the angle of refraction when light passes from air into water at an angle of 30° is approximately 22.5°.
3) The speed of light in a medium is related to its refractive index. The refractive index (n) of a medium can be calculated using the formula:
n = c / v,
where c is the speed of light in a vacuum (approximately 3 × 10^8 m/s) and v is the speed of light in the medium.
In this case, the speed of light in a plastic is given as 2.00 × 10^8 m/s.
Plugging the values into the formula:
n = (3 × 10^8 m/s) / (2.00 × 10^8 m/s)
n = 1.5
Therefore, the refractive index of the plastic is 1.5.