New trends in physics teaching, v.4; The ... - unesdoc - Unesco

New Trends in Physics Teaching IV
E. Assembling the cooker
a. Fill the floor of box A with crumpled newspapers to a depth of about 7 cm. Compress.
b. Place box B on top of the crumpled newspapers. See to it that the spaces in between the
boxes are roughly equal all round.
C. Fill the spaces in between the boxes with crumpled newspapers. Compress.
Q.5 Why should the spaces between the boxes be filled with crumpled newspapers?
d. Cover the newspapers with 2 long and 2 short card sheets.
e.
f.
g.
h.
1.
j.
Compress so these sheets are approximately ?h. cm below the top of box A. Tape them
to the walls of box A.
Place the smaller plastic sheet on top of the inner box B. (This is the second layer of
plastic sheet.) Stretch the plastic to avoid convection. Tape it to the sides.
Place the remaining card sheets on top of the plastic sheet in (0, leaving the cooking
space uncovered. Tape it to the sides of box A.
Cover outer box A with the bigger plastic sheet and tape it to the outer side.
Carefully fit the door to the cooker. Be sure that the box is sealed.
Attach the reflector to the box by taping it lengthwise to the box. (See figure 5.) This is
your box type solar oven.
plast ,IC
sheet
box
aluminium foilZ
cardboard
Figure 5.
Q.6 What are the main parts of the solar cooker?
F. Place the solar cooker you have just constructed on a sunny area.
G. Orient the cooker so that the lower end is at the south I while the taller end is at the north.
1. Editor’s note: The cooker was designed for use in the Northern hemisphere. The ends should be interchanged South of the
Equator.
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