Question 17
You will need:
a tall box or carton, two small square plane mirrors, a pencil, a ruler, a protractor to measure the angles, scissors, tape
1 Draw a sloping line across the top half of the box at 45° to the horizontal. Draw another sloping line across the bottom half of the box at the same angle. Make the lines the same length as the mirrors.
2 Cut along the top line and the bottom line. Make each cut wide enough and long enough for the mirror to slide in.
3 Draw and cut slits on the opposite side of the box in line with the cuts you have already made.
4 Push a mirror through each pair of slits. The top mirror must have its reflecting surface facing down. The bottom mirror must have its reflecting surface facing up.
5 Cut a square window in front of the top mirror. This is so that light can enter and reach the top mirror.
6 On the other side of the carton cut a small hole in front of the bottom mirror. This one is your viewing window.
7 Test your periscope.
a tall box or carton, two small square plane mirrors, a pencil, a ruler, a protractor to measure the angles, scissors, tape
1 Draw a sloping line across the top half of the box at 45° to the horizontal. Draw another sloping line across the bottom half of the box at the same angle. Make the lines the same length as the mirrors.
2 Cut along the top line and the bottom line. Make each cut wide enough and long enough for the mirror to slide in.
3 Draw and cut slits on the opposite side of the box in line with the cuts you have already made.
4 Push a mirror through each pair of slits. The top mirror must have its reflecting surface facing down. The bottom mirror must have its reflecting surface facing up.
5 Cut a square window in front of the top mirror. This is so that light can enter and reach the top mirror.
6 On the other side of the carton cut a small hole in front of the bottom mirror. This one is your viewing window.
7 Test your periscope.
