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 $20m/s$ horizontally. The shortest time in which the speed may be attained without spilling any oil is :

• A. $20s$
• B. $18s$
• C. $10s$
• D. $5s$

Answer 1

The correct option is A $20s$

$v=u+a_{x}t,a_x=v/t$

$tan\theta =\frac{a_x}{g}=\frac{v}{tg}=\frac{0.5}{5}$ (in triangle ABC)

$\Rightarrow t=\frac{10\times 20}{10}=20s$