Hot Air Balloons
10 points extra credit
Make a Hot Air Balloon according to the directions (size, shape, etc.).
Launch balloon successfully when back from break in chemistry class.
o Balloon stays aloft for minimum of 20 seconds.
Answer the analysis questions.
Cut five 50x130 cm panels of tissue paper and fold each in the middle lengthwise as shown. Cut the shaded portions out
and place one panel on a large flat surface. Place a second panel over it so all but 3 mm of tissue paper along one
border are overlapping. Smear glue down the margin of the top panel and then fold the border of the bottom panel
onto the glue to seal the seam. Repeat this process with all five panels until the pentadecahedron is complete. Glue a
strip of construction paper or other heavy paper around the base of the balloon. Punch three holes in this paper and
suspend a small paper clip by threads as shown.
1. Would hot air balloons rise faster on cool or warm days? Explain why and be sure to mention density,
pressure, and volume in you answer.
2. Why did our hot air balloons eventually fall back to earth?
3. Assume the volume of the hot air balloons we made are 500 liters. If the air temp filling the hot air balloons
starts at 650 F ( 18.30 C) and is heated to 1000 F (37.80 C), what is the new volume the heated air takes up?
Show your work.
4. If the density of dry air at STP is 1.293 g/L, using the information from problem three, calculate the density
of the air filling the hot air balloons filled at 650 F air and the density of the balloon when the temperature is
raised to 1000F. (Assume that there is no loss of mass as the temperature is raised and assume that the
pressure on the balloons is one atmosphere)