5. When light enters the eye refraction takes place at the air/cornea interface. Assuming the eye to be filled with a homogeneous medium of refractive index 1,34, calculate what radius of curvature of the cornea is necessary in order that the focal point be at the retina, 25 mm from the pole of the cornea. [I PQRD exam 1972] (6,34 mm)

In Section 9.6, we described how the speed of light varies with wavelength (or frequency) for transparent solids. But the speed of light in matter is also a function of temperature and pressure. This dependence is most marked for gases and is instrumental in producing such things as mirages and atmospheric refraction, the latter phenomenon being the displacement of an astronomical object (like the Sun or another star) from its true position because of the passage of its light through the atmosphere. Because Earth’s atmosphere is a gaseous mixture and easily compressed, its density is highest near Earth’s surface and gradually declines with altitude. (Refer to the discussion in Section 4.4 and Figure 4.29.) Thus, the speed of light in the atmosphere is lowest near the surface and gradually gets higher, approaching c as one goes farther and farther into space. Using this fact and the law of refraction, sketch the path a light ray from the Sun would follow upon entering Earth’s atmosphere, and predict the apparent position of the Sun relative to its true position (Figure 9.85). What does this tell you about the actual location of the Sun’s disk relative to your local horizon when you see it apparently setting brilliantly in the west in the evening?

Suppose a certain person’s visual acuity is such that he can see objects clearly that form an image 4.00mhigh on his retina. What is the maximum distance at which he can read the 75.0-cm-high letters on the side of an airplane?

What is the power of the eye when viewing an object 50.0 cm away?

The accommodation limits for a nearsighted persons eyes are 18.0 cm and 80.0 cm. When he wears his glasses, he can see faraway objects clearly. At what minimum distance is he able to see objects clearly?

Two stars that are 109km apart are viewed by a telescope and found to be separated by an angle of 105 radians. If the eyepiece of the telescope has a focal length of 1.5 cm and the objective has a focal length of 3 meters, how far away are the stars from the observer?

The projection lens in a certain slide projector is a single thin lens. A slide 24.0 mm high is to be projected so that its image fills a screen 1.80 m high. The slide-to-screen distance is 3.00 m. (a) Determine the local length of the projection lens, (b) How far from the slide should the lens of the projector be placed so as to form the image on the screen?

Suppose a man stands in front of a mm-or as show below. His eyes are 1.65 m above the floor and the top of his head is 0.13 m higher. Find the height above the floor of the top and bottom of the smallest minor in which he can see both the top of his head and his feet. How is this distance related to the man’s height?

The headlights of a car are 1.3 m apart. What is the maximum distance at which the eye can resolve these two headlights? Take the pupil diameter to be 0.40 cm.