An open tank `10 m` long and `2 m` deep is filled up to `1.5 m` height of oil of specific gravity `0.82`. The tank is uniformly accelerated along its length from rest to a speed of `20 m//s` horizontally. The shortest time in which the speed may be attained without spilling any oil is

Options

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

Answer

A

Explanation

`v =u+a_(X)t,a_(X)=(v)/(t)`
`tan theta=(a_(X))/(g)=(v)/(tg)=(0.5)/(5)`
(in triangle ABC)
`rArr t = (10xx20)/(10)`
`rArr 20 sec`