Rachel McBride received an honourable mention for her project at the national science fair competition in Saskatoon, Sask. earlier this month.
McBride’s project was on which material would hold up better as a swimsuit used primarily in chlorinated water.
She had discovered that suits with a higher content of spandex and a lower content of nylon were weaker. To reach this conclusion, she soaked the suits for 48 hours in a highly-concentrated water solution.
“The bleach was 3,000 parts per million in the water,” she noted. “In a pool, it is three parts per million.”
McBride then dried them, cut them into strips that were 1 cm wide, and punched a small hole in each of them. They then were hooked onto a Newton scale and pulled until they broke.
The highest tolerance was 55 Newtons—and it was from the suit with the least amount of spandex.
McBride travelled to the national competition with Heidi Friesen, a fellow student at the Sturgeon Creek Alternative Program in Stratton.
Friesen’s experiment involved bicycle safety helmets.
“I wanted to see if the shape and ventilation design of a helmet would affect the cooling of a head in a breeze,” she said.
Using a streamlined helmet and a round one, Friesen first thought the
streamlined one would allow the head to cool the fastest because of where the ventilation holes were located.
Putting a water balloon filled with water at 37° C, she placed the helmeted balloon in a wind-tunnel. To her surprise, the rounded helmet allowed the water in the balloon to cool faster.
“The air moves faster over a rounded helmet, creating a lower pressure over its surface and hot air can then escape faster,” she explained.
Friesen had received an honourable mention at the national showdown last year in Kingston.
McBride and Friesen, both in Grade 8, advanced to the national science fair after placing second and third, respectively, behind Jordan Hatch of Dryden in the Sunset Country Regional Science Fair held April 13 at Crossroads School in Devlin.
Both said it was a good experience.