Final answer:
To find the index of refraction for an unknown substance through which a ray of light passes from air, Snell's Law can be used; however, the question must provide clear information on the incident and refracted angles for an accurate calculation.
Step-by-step explanation:
Calculating the Index of Refraction
To calculate the index of refraction (n value) of an unknown substance when a ray of light travels from air into it, we use Snell's Law: n1 * sin(θ1) = n2 * sin(θ2). The index of refraction for air (n1) is typically considered to be 1. When the angles of incidence (θ1) and refraction (θ2) are known, the only unknown is the index of refraction for the second substance (n2), which can then be solved for. If the angles given (73 and 77) represent an incident angle and a refracted angle respectively, Snell's Law allows us to calculate n2. However, without specific information on what the angles represent and which medium they pertain to, or any units associated with them, a precise calculation is not feasible with the given data.
It is important to ensure that the angles provided are in degrees and correspond to the incident and refracted angles with respect to the normal at the interface of the two media.