The focal length of the lens of a simple digital camera is 40 mm, and it is originally focused on a person 25 m away. In what direction must the lens be moved to change the focus of the camera to a person 4.0 m away?

Two lenses are placed along an optical rail. One is a converging lens, with a focal length of f1 = 30.3 cm. The second lens, a diverging lens with a focal length of f2 = −20.0 cm, is placed d = 110 cm to the right of the converging lens. An object ho = 2.02 cm high is placed p1 = 40.5 cm to the left of the converging lens. (a) Determine the position of the final image. (Enter the position in cm relative to the diverging lens.) magnitude  ? cm direction  right or left?   of the diverging lens   (b) Determine the magnification of the final image. (Indicate the orientation with the sign of your answer.)  Hint* The total magnification is the product of each individual magnification. (c) Is the image upright or inverted?    (d) Repeat parts (a) through (c) for the case in which the second lens is a converging lens having a focal length of 20.0 cm. (Enter the position in cm relative to the second lens. Indicate the orientation of the magnification with the sign of your…

In a two-lens system, the focl length of the lens is f1 = 4.00 cm, and that of then lens 2 is f2 = 8.00 cm. The distance between the lenses is 16 cm. If an object O is 2.00 cm high and is placed 6.00 cm in front of the lens 1, where is the final image through the two-lens system?

The owner of a van installs a rear-window lens that has a focal length of -0.310 m. When the owner looks out through the lens at an object located directly behind the van, the object appears to be 0.250 m from the back of the van, and appears to be 0.330 m tall. (a) How far from the van is the object actually located, and (b) how tall is the object? Rear-window lens (a) Number i (b) Number i Units Units Person Image of person

What is the focal length of the lens in your eye when you can focus on an object at your near point? Assume that the distance from your lens to the back of your eye is 2.0 cm, that your near point is 21 cm in front of your lens, and that the liquid behind the lens has n=1.00 just like the air in front of your lens. (a) 1.8 cm (b) 18 cm (c) 2.1 cm (d) 21 cm (e) None of the above.

An object is initially at rest, 100 cm from a converging lens with a focal length of 30.0 cm. The object accelerates toward the lens at a constant rate of 0.300 cm/s?. At what time will the magnification of the image produced be -2.00?

A 1.00-cm-high object is placed 3.95 cm to the left of a converging lens of focal length 7.80 cm. A diverging lens of focal length –16.00 cm is 6.00 cm to the right of the converging lens. Find the position and height of the final image. position 7.5 cm in front of the second lens v 0.5466 height Calculate the magnification produced by each lens. Then consider how the magnification relates image size and object size for each lens to find the height of the final image. cm Is the image inverted or upright? upright O inverted Is the image real or virtual? real virtual

The distance between the eyepiece and the objective lens in a certain compound microscope is 10.4 cm. The focal length of the objective is 0.430 cm, and that of the eyepiece is 1.40 cm. Find the overall magnification of the microscope. (The near point of the eye is 25 cm. Assume that the object is placed at the focal point of the objective lens, and one places the eyepiece at the near point of the eye.)

A nearsighted person has a far point of 25.3cm and is prescribed contact lenses to correct her vision. What lens strength (a.k.a., lens power), in Diopters, should be prescribed? Give your answer using the usual convention of positive values for converging lenses and negative values for diverging lenses.