A light source is placed in the middle of a surface of a swimming pool at depth of 2 m . If the refractive index for the water is (1.33) and the surface of the swimming pool is squared shaped with a length of 2 m , what is the angle of refraction of the light ray ( coming out of the pool ) to the air if the refractive index of the air is 1.

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg