1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Questions On Security Mirrors ! Help

  1. May 31, 2008 #1
    Questions On Security Mirrors!!!!!! Help!!!

    Hello anyone who can help me!

    I am from Aus, Yr 9 and need some help for an assignment.

    Here are the questions:

    What type of mirror is used in shops as the Security mirror? - i have already answered this

    Why is this type of mirror used?- have half answered this question so more info would be great.

    How do scientists describe the type of image it produces?- this is the question i really need help on!

    Thanks again

    forda11

    P.S is this answer right- Why did Apollo 11 Astronauts deliberately live a mirror on the moon in 1969- is it to reflect laser beams from the earth???
     
  2. jcsd
  3. May 31, 2008 #2
    hahaha adelaide
    its lucy from penrhos. i was looking for info on my science assignment and i clicked on this website and i saw what you wrote. hahahaa. i cant find any info. :(
    xx lucy
     
  4. May 31, 2008 #3
    Well, security mirrors are used when the securty wants to see you but not you seeing them.
    This is acheived by having a partialy reflective surface on your side, but none on the other side. The effect causes some darkening with respect to the view of the security observer, but well within the limits of the law.
     
  5. Jun 1, 2008 #4
    Thanks for your help- much appreciated. And hi Lucy- what a coincedence!!! forda11
     
  6. Jun 2, 2008 #5

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi forda11! Welcome to PF! :smile:
    No, I don't think the question means those, because it asks:
    Those mirror don't provide an image at all (well, not for the security officers to see).

    I think the question means the ordinary curved mirrors that give a view of most of the shop. :smile:
     
  7. Jun 2, 2008 #6
    What type of mirror is used in shops as the Security mirror? convex mirror - always virtual image and large covering area of sight.

    Why is this type of mirror used?- always gives virtual image and large area of sight covered due to outward curvature.

    How do scientists describe the type of image it produces? virtual diminished image.

    P.S is this answer right- Why did Apollo 11 Astronauts deliberately live a mirror on the moon in 1969- is it to reflect laser beams from the earth?

    Dateline - 21 July 2004: Apollo 11 science experiment left on the Moon is still being used

    35 years ago, a 600 mm wide panel studded with 100 mirrors pointing at Earth - the "lunar laser ranging retroreflector array" - was placed on the Moon. Apollo 11 astronauts Buzz Aldrin and Neil Armstrong put it there on July 21, 1969, about an hour before the end of their final moonwalk. It is the only Apollo science experiment still working today. Astronomers on Earth bounce laser beams off it to measure the exact Moon's distance at a given moment, with an accuracy of a few centimetres over a distance of nearly 400 000 kilometres.
     
  8. Jun 3, 2008 #7
    haha heyy ade and lucy lol. any way i need help too for the same assignment - its pretty hard haha.

    my questions are

    What type of mirror is used in a reflective telescope, like the hubble space telescope? why is this type of mirror used?

    thankyou very very very much. and also its due tomorroww
     
    Last edited: Jun 3, 2008
  9. Jun 3, 2008 #8
    A parabolic concave reflector to focus the light's rays, and avoid any optical aberrations.
     
  10. Jun 3, 2008 #9
    im sorry spideyunlimited thankyou very much but could you say it in a different way with easier to under stand words? thanks
     
  11. Jun 3, 2008 #10
    what didn't you understand? :S
    a concave mirror is used.. either parabolic or spherical..
    it's used to focus the light rays.

    using a parabolic one also avoids optical aberrations like chromatic or spherical aberrations... I think you don't have to worry about them at this stage.
     
  12. Jun 3, 2008 #11
    :surprised
     
  13. Jun 5, 2008 #12
    i dont get this either :S!!
     
  14. Jun 5, 2008 #13
    lol what can i do now
     
  15. Jun 5, 2008 #14

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    ah … spideyunlimit … you've just learned a golden rule the hard way …

    try to get the OP to answer the question in their own words …

    that way you find out what their state of knowledge is …

    nudging is better than dragging! :smile:
    Hi rippec11! :smile:

    What types of mirror have you been taught about?

    Which type do you think would be useful in a reflecting telescope? :smile:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Questions On Security Mirrors ! Help
  1. Help with mirrors? (Replies: 3)

  2. Help! mirror question! (Replies: 2)

  3. Mirrors question (Replies: 1)

Loading...