Open Oregon Educational Resources
Hydraulics and Electrical Control of Hydraulic Systems
It's all systems go for learning about hydraulic systems. An eBook provides a set of videos and exercise questions for a semester-long course on hydraulics. Six units introduce hydraulics, Pascal's law, hydraulic applications, flow...
Utah Education Network (UEN)
Utah Open Textbook: Biology
Curriculum resources can be expensive—but not this one. An online textbook offers informational text for a complete high school Biology course. Topics include energy flow, body system, genetics, and evolution.
Libre Text
Libre Text: Pressure Gradients
From high school geography class, you may remember that "air tends to flow from high pressure to low pressure". To understand why this happens, it is key to realizing that gasses (but also liquids) exert a force on their surroundings...