Lights and Mirrors Labs

 

First Things First:  Make sure that you have everything in your “Box-O-Light”.  There should be a note card in there which tells you what’s in it.  Be sure that your lighter works and the maglight has batteries in it too.

 

Second things second:            You can write your answers right in this document and then send it to my e-mail address.  Be sure to put the names of all of the members of your group up at the top of this page.

 

Fish Tank – o – Water Experiments

1.  Come up to the fish tank and use the maglight supplied to find the following.

            a.  Critical angle of internal reflection (qc).  You may find this qualitatively.

           

Flat Mirror Experiments

1.  Attach the flat mirror (in your “box-o-light” stuff) with a piece of tape to the block-o-wood in your box.  Set it up on your table and hold a pencil 10.0 cm away from the mirror.

            How far BEHIND the mirror must you put another pencil in order for the image of the pencil appear to be the same size as the pencil you placed behind the mirror?

                        ___________________cm  (recall, for a flat mirror, do = di)

 

2.  Tape your flat mirror to a wall in the classroom and look at your ugly mug in it.  Walk backwards, away from the mirror.  Do you see any more of yourself as you move away?  __________________

 

3.  Convince other groups to loan you their mirrors (ask nicely).  Tape these to the wall in a vertical fashion until you have enough mirrors to see your entire body.  How long is your vertical column of mirrors compared to the length of your body.  (answer in either a fraction or percentage of your actual height). _________________

 

4.  True or False:  As you back away from a mirror, you can see more of your body.  _________

 

Concave (converging) Mirror Experiments

 

Answer the following:  (be sure to use proper + or – signs when answering)

 

When do = 5 cm, di = _______________      M = _____________   hi = ____________

When do = 3 cm, di = _______________      M = _____________   hi = ____________

When do = 10 cm, di = ______________      M=  _____________   hi = ____________

 

Are the images from the concave mirror:

            a.  always virtual     b.  always real     c.  either virtual or real.  ___________answer here

 

Useful Formulas:

di = dof/do-f

M = -di/do = hi/ho  (pay particular attention to when to use minus signs and when not to)

 

Convex (diverging) Mirrors Experiments

 

Answer the following:  (be sure to use proper + or – signs when answering)

 

When do = 5 cm, di = _______________      M = _____________   hi = ____________

When do = 3 cm, di = _______________      M = _____________   hi = ____________

When do = 10 cm, di = ______________      M=  _____________   hi = ____________

 

Are the images from the convex mirror:

            a.  always virtual     b.  always real     c.  either virtual or real.  ___________answer here

 

Useful Formulas:

di = dof/do-f

M = -di/do = hi/ho  (pay particular attention to when to use minus signs and when not to)

 

BiConcave (diverging) LENS Experiments (notice that concave lenses are diverging.  Concave mirrors are converging):

 

Answer the following:  (be sure to use proper + or – signs when answering)

 

When do = 5 cm, di = _______________      M = _____________   hi = ____________

When do = 3 cm, di = _______________      M = _____________   hi = ____________

When do = 10 cm, di = ______________      M=  _____________   hi = ____________

 

Are the images from the Biconcave lens:

            a.  always virtual     b.  always real     c.  either virtual or real.  ___________answer here

 

Useful Formulas:

di = dof/do-f

M = -di/do = hi/ho  (pay particular attention to when to use minus signs and when not to)

 

BiConvex (converging) LENS Experiments  (notice that covenx lenses are converging.  convex mirrors are diverging):

 

Answer the following:  (be sure to use proper + or – signs when answering)

 

When do = 5 cm, di = _______________      M = _____________   hi = ____________

When do = 3 cm, di = _______________      M = _____________   hi = ____________

When do = 10 cm, di = ______________      M=  _____________   hi = ____________

 

Are the images from the Biconvext lens:

            a.  always virtual     b.  always real     c.  either virtual or real.  ___________answer here

 

Useful Formulas:

di = dof/do-f

M = -di/do = hi/ho  (pay particular attention to when to use minus signs and when not to)