A ray of light travelling in air strikes water by making angle 30 calculate angle of reflection if refractive index of glass is 1.5
30deg to horizontal or vertical?
In either case, use Snell's law.
To calculate the angle of reflection, we need to apply the law of reflection, which states that the angle of incidence is equal to the angle of reflection.
Here's how you can calculate it:
1. Start by drawing a diagram with a ray of light traveling from air (let's call this medium 1) and striking water (medium 2) at an angle of 30 degrees.
2. To find the angle of incidence, measure the angle between the incident ray and the normal (a line perpendicular to the water's surface). In this case, the angle of incidence is 30 degrees.
3. Now, we need to find the angle of refraction when the light ray enters the glass (medium 3). Use Snell's law, which states that the ratio of the sines of the angles of incidence and refraction is equal to the ratio of the refractive indices of the two media.
Mathematically, Snell's law can be written as:
n1 * sin(angle of incidence) = n2 * sin(angle of refraction)
Since we know the refractive index of air is approximately 1, we can write:
1 * sin(30) = 1.5 * sin(angle of refraction)
4. Rearrange the equation to solve for the sine of the angle of refraction:
sin(angle of refraction) = (1 * sin(30)) / 1.5
5. Calculate the value of sin(angle of refraction) using a scientific calculator or an online calculator.
6. Once you have the value of sin(angle of refraction), use the inverse sine function to find the angle of refraction.
angle of refraction = sin^(-1)(sin(angle of refraction))
This calculation will give you the angle of refraction when the light ray enters the glass. However, since you asked for the angle of reflection, we can simply use the law of reflection, knowing that the angle of incidence equals the angle of reflection. Therefore, the angle of reflection would also be 30 degrees.