Open container accelerating vertically upward: effect on pressure at the bottom An open container completely filled with water is moved vertically upward with a uniform linear acceleration. Compared with the static case at rest, how does the pressure at the bottom change?

Introduction / Context:
Accelerating containers create an apparent body force field in addition to gravity. In vertical accelerations, the hydrostatic pressure distribution is modified by an effective gravity g_eff, impacting bottom pressures and gauge readings.

Given Data / Assumptions:

• Open container, water fully filling the container.
• Uniform upward linear acceleration a.
• Neglect sloshing and compressibility; quasi-static distribution.

Concept / Approach:
In a non-inertial frame accelerating upward with acceleration a, the effective body force per unit mass is (g + a) downward. Hence pressure varies as p = rho * (g + a) * h below the free surface (which stays horizontal for uniform acceleration).

Step-by-Step Solution:

Verification / Alternative check:
Energy viewpoint: additional inertial field increases potential gradient, thus higher pressure at the same depth.

Why Other Options Are Wrong:

• Equal/lesser: contradict the increase in effective gravity.
• None of these: there is a definite, predictable increase.

Common Pitfalls:
Confusing upward vs downward acceleration; for downward acceleration, effective gravity is (g − a) and pressure reduces (becoming zero at free fall).

Final Answer:
greater than static pressure