Question

I have a container that is $20cm$ tall and filled fully with water. The lift accelerates up at $10m/s^2$. What is the pressure difference between the top surface of the water and the bottom of the container? Take density of water as $1kg/lit$ and acceleration due to gravity $g$ = $10m/s^2$

• A. $2\times {10}^4$
• B. $8\times {10}^4$
• C. $4\times {10}^4$
• D. $16\times {10}^4$

Answer 1

The correct option is C

$4\times {10}^4$

Given,

Height $h$= $20cm$

Accelaration of lift $a$ = $10m/s^2$
Since the container is accelerating up, effective g will be
g' = g+a = 10+10 = $20m/s^2$

The pressure difference from top to bottom will be given the equation $\rho gh$
$h\rho g=0.2\times 1000\times 20$
$=4\times {10}^{4}Pa$