SNC2D Convex & Concave Mirrors Lab Activity

Name: ______

Date: ______

SNC2D Convex & Concave Mirrors Lab Activity

Materials:

·  convex mirrors

·  ray box

·  ruler

·  large sheet of white paper

Procedure:

Part A – Finding the Focus

1.  Place a convex mirror on the far right side of the paper. Make some markings (or trace around the mirror) so you can replace the mirror if you knock it.

2.  Aim the ray box so that it perpendicular to the vertex and reflects straight back from the mirror. This is your principle axis. Trace this line with your ruler.

3.  Place the ray box above the principle axis and aim the ray box toward the mirror ensuring that the beam is parallel. Trace the incident ray and extend the reflected ray back behind the mirror.

4.  Repeat step 5, placing the ray box below the principle axis.

5.  Mark the focus (the point where the rays cross behind the mirror).

6.  Measure the focal length.

7.  Leave everything set up for Part B

Part B – Finding the Centre of Curvature

1.  Re-aim the ray box so that the beams reflect straight back on each other. Trace this line with your ruler and extend the ray behind the mirror.

2.  Repeat step 1 moving the ray box to another location

3.  Label the point where these rays cross behind the mirror. This is the centre of curvature.

Questions:

1.  On your diagram, label the following: vertex (V), principle axis (PA), focus (F), centre of curvature (C)

2.  Measure the focal length. ______cm

3.  Measure the length from the vertex to the centre of curvature. ______cm. How does this measurement relate to the focal length?

4.  Where do the light rays appear to cross? In front of or behind the mirror?

5.  List the image characteristics (LOST) for diverging mirrors.

Part C – Comparing Concave and Convex Mirrors.

1.  Place the 5 slit baffle onto the ray box (remove any tape that is blocking the slits).

2.  Shine the ray box at a concave mirror. What do notice?

3.  Shine the ray box at a convex mirror. What do you notice?

Questions:

1.  Using your observations, explain why a concave mirror is also called a converging mirror and a convex mirror is also called a diverging mirror.

2.  Examine the image of the TV satellite. What type of mirror does it resemble? Where would be the best location for the receptor? Explain.

3.  Car mirrors read “Objects in mirror are closer than they appear”. Do you think car mirrors are concave or convex? Justify your choice. (HINT: Think about LOST)

4.  Examine the image made in a make-up mirror. Do you think make-up mirrors are concave or convex? Justify your choice. (HINT: Think about LOST)