physics

posted by .

A slide is 5 inches high. it is placed 5.5 inches from the convex lens of a porjection lantern. The image is cast upon a screen 55 inches away. the focal length of the lens is ______inches?
b) the heigh of the image cast by the lens is ________inches?

  • physics -

    (a) Use the lens formula.
    1/5.5 + 1/55 = 1/f
    Solve for the focal length, f.
    10/55 + 1/55 = 11/55 = 1/5 = 1/f
    One more step.

    (b) image height = (object height)x(55/5.5)
    = 5*10 = ___ inches

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics: Lenses

    1) A convex lens with a focal lenght of 4.0cm is placed 20.0cm from a concave lens with a focal lenght of 5.0cm. Find the position of the image when the object is placed 12.0c, in front of the convex lens. 2) A double concave lens …
  2. Science Important

    1. A toy of height 18.4 cm is balanced in front of a converging lens. An inverted, real image of height 33 cm is noticed on the other side of the lens. What is the magnification of the lens?
  3. Physics

    An image of a candle is produced by a convex lens 14 cm away. If the focal length of the lens is 7 cm, how far from the lens is the candle placed?
  4. college physics

    A 4.5 cm long insect is perpendicular to the optical axis of a thin lens; the bug is 5.4 cm away from the lens. The lens forms an inverted image of the insect which is 0.9 cm long on a screen behind the lens. a. How far behind the …
  5. physics

    A certain LCD projector contains a single thin lens. An object 23.5 mm high is to be projected so that its image fills a screen 1.87 m high. The object-to-screen distance is 3.05 m. (a) Determine the focal length of the projection …
  6. physics

    A box is placed 50 cm away from a double convex lens. The image is on the opposite side of the lens, is inverted and 50 cm away from the lens. find: a)the focal length of the lens. b)the height of the image. c) using the focal length …
  7. Physics

    i have a question on thin lens equation how do i know when di is positive or negative?
  8. physics

    Because a concave lens cannot form a real image of a real object, it is difficult to measure its focal length precisely. One method uses a second, convex, lens to produce a virtual object for the concave lens. Under the proper conditions, …
  9. Physics

    A thin convex lens produce a real image on an a screen . if an object of height 36mm is placed 2000mm from the screen ,an image of height 684mm will be produced .determine A) the distance of the object from the lens B) the focal length …
  10. physics

    A pin 2 cm long is placed 12 cm away from a convex lens at right angles to the principal axis. If the focal length of the lens is 20 cm, by scale drawing and lens formula find the nature , size and position of image.

More Similar Questions