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Air
- Sail Away! - Episode 110
  
Sailing
Emmanuel
and GiGi love to sail their toy boats in Central Park and noticed
that their boats seem to travel faster in some directions than
in others.
Question
What is the fastest sailing direction, and why?
Investigation
They sailed their model boat in three directions: with the wind
(called "running"), with the wind, but at an angle (called
"broad reach"), and into the wind at an angle (called
"close hauled"). Once they found the fastest direction,
they tried the same experiment on a real boat.
Results
| |
model
boat speed
|
real
boat speed
|
| Running |
0.22
m/sec
|
5
knots
|
| Broad
Reach |
0.33
m/sec
|
7
knots
|
| Close
Hauled |
0.24
m/sec
|
6
knots
|
|
Conclusion
Emmanuel and GiGi found that broad reach was the fastest sailing
direction for the model boat and the real boat. On the real boat
they also used an anemometer and discovered that the wind speed
was different on the two sides of the sail.
Balloons
Masha and Patsy were fascinated by the grace and speed of colorful,
gigantic hot air balloons, and wondered how something bigger than
a house could float through the air.
Question
How
does hot air lift things?
Investigation
The girls booked a ride in a hot air balloon and recorded the
temperature and the variometer (changing altitude) reading.
Conclusion
They learned that the hotter the temperature, the faster the balloon
rose, and that even hovering required a high temperature.
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