Watching Paint Dry
Reducing the amount of paint used and time in between coats is an important optimization problem for manufacturers.Copyright 2008 RoboGuru, CC BY-SA 3.0, Wikimedia Commons, https://en.wikipedia.org/wiki/Automotive_paint#/media/File:P-50iA.jpg
Students take on the task of designing a container that holds exactly one spritz of water from a spray bottle. They measure the mass of the collected liquid, or spritz, and calculate how long it takes for the water to vaporize using a formula for an experimental rate of evaporation. After understanding the rate of evaporation, students iterate their designs and practice dimensional analysis to further analyze their data.
Achieving rapid drying times are a crucial component of engineering. Adhesives and building materials, if applied in liquid form, must cure, harden, or dry before the next step in the manufacturing process. A more precise drying time may lead to a more efficient engineering process overall. Students are tasked with taking on the role of engineers to calculate drying time by examining the amount of water expelled from a spray bottle into a controlled space.
After this activity, students should be able to:
- Determine the mass of an unknown amount of liquid.
- Use iterative design to validate test results.
- Employ dimensional analysis to convert one unit to another with a given rate in mind.