Answer:
To use Snell's law to find N1, we need to know the indices of refraction and angles of incidence and refraction of the two media.
Snell's law states that:
n1 sin(theta1) = n2 sin(theta2)
where n1 and n2 are the indices of refraction of the two media, theta1 is the angle of incidence, and theta2 is the angle of refraction.
We are given n2=2.61, theta1=40°, and theta2=34°. To find N1, we need to rearrange Snell's law to solve for n1:
n1 = n2 sin(theta2) / sin(theta1)
Plugging in the values we have:
n1 = 2.61 sin(34°) / sin(40°)
n1 ≈ 2.22
Therefore, the index of refraction of the first medium (N1) is approximately 2.22, based on the given values and Snell's law.