Question

Consider two water tanks filled with water. The first tank is 8 m high and is stationary, while the second tank is 2 m high and is moving upward with an acceleration of 3.5 m/s2. Which tank will have a higher pressure at the bottom

Answer 1

Answer:

The first tank has a higher pressure at the bottom because it has  more depth

Explanation:

height of first tank = 8 m

height of second tank = 2 m

acceleration of second tank = 3.5 m/$s^{2}$

first calculate the pressure of the first tank :

pressure = pgh --- equation 1

where p = 1000 (pressure constant)

g = 9.81 ( acceleration due to gravity )

h = height

back to equation 1

pressure = 1000 * 9.81 * 8 = 78480 N/$m^{2}$

for the second tank

using equation 1

pressure = pgh

g = 9.91 + 3.5

h = 2 m

since the second tank has an acceleration we have to add it to the acceleration due to gravity so

pressure = 1000 * ( 9.81 + 3.5 ) * 2

               = 1000 * 13.31 * 2

               = 26620 N/$m^{2}$

Answer 2

Answer:

The second tank would have a higher pressure at the bottom.

Explanation:

Pressure in a vessel is given as the product of the height of the vessel (h), density of the fluid in the vessel (rho) and acceleration due to gravity (g).

For the first tank:

h = 8 m, rho = 1000 kg/m^3, g = 0 m/s^2 (tank is stationary)

P = h×rho×g = 8×1000×0 = 0 Pa

For the second tank

h = 2 m, rho = 1000 kg/m^3, g = 3.5 m/s^2

P = h×rho×g = 2×1000×3.5 = 7,000 Pa

The second tank would have a higher pressure because it is in motion.