An object falling through a static water column is observed to have an acceleration given by the relation ang-bu where g is acceleration due to gravity and 'b' is a constant. After sufficiently long time of its release, it is observed to fall with a constant speed. What must be the value of its constant speed ?

Options

A. v=g/b
B. v=a/b
C. v=g`xx`b
D. None of these

Answer

a

Explanation

Acceleration a=g-bv
After a long intervel the viscous restisance become constant and body begins to fall with a consatnt speed. As at that moment a=0
`:.` 0=g-b.v
`:.` bv=g or v=g//b