Last week, Mackenzie presented the Hawks with a water timer challenge when she realized there was a piece missing from their understanding of how flow rates of water in a container make it impossible to have regular marked intervals on a water timer. She grouped the band into research pairs and they explored how changing one variable affects the whole system when the other variables are held constant. Bruno and Clementine experimented with the height of the cup, Ben and Natasha experimented with the volume of water, and Lola and Quinn experimented with the size of the container.
They presented their discoveries to the group after a morning of giggling and playing with water in the trough sink in the art studio.
Natasha and Ben took their work to the next level after showing each other how volume effects water pressure by drilling a larger hole into one of the bottles. Mackenzie says that they “were figuring out what the water levels of each bottle would need to be for them to drain out in the same time” and that “Ben’s excitement really ignited Natasha and Natasha helped keep Ben focused and on task.”
Clementine and Bruno tried to figure out how elevation affected water pressure. Clementine had the idea of attaching containers to a post and Bruno decided that all of the containers had to be the same size. They were able to discuss and collaborate on sources of error in their design, and had a successful run through, but Mackenzie says, “Unfortunately their experiment kept confirming their theory that elevation affects flow rate! Since their experimental design was so spot on I didn’t correct their assumption, but the following day I made a demonstration that called their conclusions into question and explained that gravity exerts the same force on everything no matter the height.” This next discovery still puzzles and astonishes the group – and some of the adults!
Lola and Quinn took on the idea the shape of the water container affecting flow rates and water pressure, and were able to create a demonstration showing just that after sitting down with Mackenzie to learn just exactly what the point is of variables and constants. She says, “Lola was so stoked by this discover that she spent her library time writing three pages of notes discussing her theory on why water pressure is higher in a tall skinny container than a fat wide one.”
Mackenzie says, “So where are we planning on going from here? Every clock needs to have a constant flow of energy. The crux of a water clock is figuring out how to keep the water pressure constant. Equipped with their new understanding of fluid dynamics the Hawks are going to try and build water clocks capable of keeping regular intervals of time!” She says that they will be moving into making mechanical clocks soon as well.