🔍 Key Concepts

• Hydraulic oil compressibility at high pressure • Typical percent volume change of liquids under pressure • Difference between ideal (theoretical) incompressible liquid and real hydraulic fluids

💭 Think About

• If a liquid were perfectly incompressible, how much would its volume change, even at very high pressure? • Think about whether the volume change for real hydraulic oil is small or large: would 100 psi cause a big change or a very tiny one? • Compare the size of the percentage change and the size of the pressure step in each option: which pair looks most realistic for a slightly compressible liquid?

✅ Before You Answer

• Estimate whether 100 psi is enough to noticeably change a liquid’s volume in percent terms • Compare options with 1% vs 0.5% change — which seems more reasonable for a liquid under pressure? • Focus on options that describe a small but not zero reduction in volume, over a relatively high pressure range