DRAWING RAY DIAGRAMS FOR CONCAVE MIRRORS
RULES:
1. Draw a straight horizontal line – this is your principal axis
2. Draw a concave mirror on the far right side of your line
3. Place your object (an arrow) on the principal axis where you are told (the focal length will be given – this is how far your object is from the mirror)
4. Place your Principal Focus (F) on the principal axis where you are told
5. Draw an incident ray (line) from the top of the arrow parallel to the principal axis until it hits the mirror – draw a line from here through the principal focus (F)
6. Draw a line from the top of your arrow at an angle through your principal focus (F) – when it hits the mirror, draw a line backwards that is parallel to the principal axis
7. Where the 2 lines meet is the top of the arrow. Draw the rest of the arrow upside down until you hit the principal axis.
Describing the Image:
S: size (larger or smaller than object)
A: attitude (upright or inverted)
L: location (same side as object or opposite side as object)
T: type (real or virtual)
PRACTICE:
Use the picture below to practice drawing the image found in a concave mirror
F
F
Draw the following ray diagrams. Write the SALT for each image.
1.) The object is 2cm high and is placed 8cm from the mirror. The focal length (f) is 3cm.
2.) The object is 1.5cm high and is placed 5cm from the mirror. The focal length (f) is 2cm.
3.) The object is 2.5cm high and is placed 10cm from the mirror. The focal length (f) is 5cm
4.) The object is 1cm high and is placed 6cm form the mirror. The focal length (f) is 2cm.
5.) The object is 1.5cm high and is placed 7cm from the mirror. The focal length (f) is 4cm.