Question

I have a container that is 20cm tall and filled fully with water. The lift accelerates up at 10m/s. What is the pressure difference between the top surface of the water and the bottom of the container? Take density of water as 1kg/l.

• 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

$4\times {10}^4$

Since the container is accelerating up, effective g will be
$g^{\prime }=g+a=10+10=20\frac{m}{s^2}$

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