The force divided by cross-sectional area equals what term?

• A. Stress
• B. Strain
• C. Pressure
• D. Density

Answer: (A)

When you divide the force by the area over which it acts, you’re measuring how intensely the material is loaded per unit area. That quantity is called stress. It represents the internal resisting force distributed over the cross-section and is measured in newtons per square meter (pascals).

Pressure is similar in concept (force per area) but is used for fluids or external contact pressures; in solids under axial loading, the appropriate term for the internal forces is stress. Strain is about how much the material deforms (a change in length), not the force per area, and density is mass per volume.