For upward motion:

\[ P_B = \gamma h \left( 1 + \frac{a}{g} \right) \]

For downward motion:

\[ P_B = \gamma h \left( 1 - \frac{a}{g} \right) \]

Where:

• \( P_B \) is the pressure exerted by the fluid at the tank’s bottom.
• \( \gamma \) is the specific weight of the fluid.
• \( h \) is the height of the fluid.
• \( a \) is the vertical acceleration.
• \( g \) is the gravitational acceleration (9.81 m/s² or 32.2 ft/s²).