Question

An open tank $10m$ long and $2m$ deep is filled up to $1.5m$ height of oil of specific gravity $0.82$. The tank is uniformly accelerated along its length from rest to a speed of $20m/sec$ horizontally. the shortest time in which the speed may be attained without spilling any oil is : $[g=10m/se{c}^2]$

• A. 10 sec
• B. 5 sec
• C. 18 sec
• D. 20 sec

Answer 1

The correct option is D 20 sec

Step 1: Draw rough figure for given situation


Step 2: Find the time in which the speed becomes $20m/s$
$v=u+a_{x}t$
$\Rightarrow a_x=\frac{V}{t}$
$\frac{a_x}{g}=\tan \theta$
$\frac{v}{tg}=\frac{0.5}{5}$$\left(\text{in triangle ABC}\right)$
$\Rightarrow t=\frac{10\times 20}{10}=20sec$

Final answer: (a)