Which formula would most likely be used in applications of Snell's law?

• A. p1V1 = p2V2
• B. n1 * sin(θ1) = n2 * sin(θ2)
• C. Q = πr^4(P1-P2)/(8ηL)
• D. f' = f(v/(v - v_s))

Answer: (B)

The formula most associated with applications of Snell's law is indeed n1 * sin(θ1) = n2 * sin(θ2). This equation describes the relationship between the angles of incidence and refraction when a wave (such as light) passes from one medium into another with a different refractive index.

In Snell's law, n1 and n2 represent the refractive indices of the two media, while θ1 is the angle of incidence (the angle between the incoming ray and the normal to the surface) and θ2 is the angle of refraction (the angle between the refracted ray and the normal). This formula is critical in understanding how light bends when it moves between materials like air and glass or water, often seen in optical applications.

The other formulas provided serve different physical contexts. The formula p1V1 = p2V2 pertains to the conservation of mass in fluid dynamics, specifically in compressible flow. Q = πr^4(P1-P2)/(8ηL) relates to Hagen–Poiseuille's equation for laminar flow of a viscous fluid through a pipe, focusing on flow rates under pressure differences. Lastly, f' = f(v/(v - v_s))