The indices of refraction for her contact lens, cornea, and the fluid behind her cornea are 1.6, 1.4, and 1.3, respectively. Light is incident from air onto her contact lens at an angle of 30 ∘∘ from the normal of the surface. At what angle is the light traveling in the fluid behind her cornea?

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

Could someone . i have tried to solve myself but my calculation is off

Does anyone know how to solve this problem? i really need . i made an attempt but i just cant get it. a metal rod is 25.000 cm long at 25.0 degrees celsius. when heated to 102.0 degrees celsius, it is 25.054 cm long. what is the coefficient of linear expansion for this metal.