A thief hides a precious jewel by placing it on the bottom of a public swimming pool. He places a circular raft on the surface of the water directly above and centered over the jewel as shown in the figure below. The surface of the water is calm. The raft, of diameter d- 2.25 m, prevents the jewel from being seen by any observer above the water, either on the raft or on the side of the pool. What is the maximum depth h of the pool for the jewel to remain unseen? d Raft Jewel

A person swimming underwater on a bright day and looking up at the surface will see a bright circle surrounded by relative darkness as in figure (a) below, a phenomenon known as Snell's window. Use the concept of total internal reflection and the illustration in figure (b) to show that ? = 97.2° for the cone containing Snell's window. (Submit a file with a maximum size of 1 MB.) HINT

A soda straw is stuck into water at an angle of 36° to the vertical. Looking straight down, what does the angle of the submerged portion of the straw to the vertical appear to be?

A person swimming underwater on a bright day and lookingup at the surface will see a bright circle surrounded by relativedarkness as in Figure P22.61a, a phenomenon known asSnell’s window. Use the concept of total internal reflectionand the illustration in Figure P22.61b to show that Θ = 97.2°for the cone containing Snell’s window.

You can determine the index of refraction of a substance by determining its critical angle. (a) What is the index of refraction of a substance that has a critical angle of 51.0° when submerged in carbon tetrachloride, which has an index of refraction of 1.461? (b) What would the critical angle be for this substance in air?

A laser beam of diameter d₁-1.1 mm is directed along the optical axis of a thin lens of focal length +4.7 cm (see figure below). (a) How far from the lens will the beam be focused? (b) A second positive lens is placed to the right of the first. Light emerges from the second lens in a parallel beam of diameter dy 3.6 mm. Thus the combination of lenses acts as a beam expander. Find the focal length of the second lens. Find the distance between the lenses.

MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A mirror hangs 1.80 m above the floor on a vertical wall. A ray of sunlight, reflected off the mirror, forms a spot on the floor 1.07 m from the wall. Later in the day, the spot has moved to a point 2.50 m from the wall. (a) What is the change in the angle of elevation of the Sun, between the two observations?