An object falling through a fluid is observed to have acceleration given by ` a= g- bv` where ` g= gravitational acceleration and (b) is constant. After a long time of rlease. It is observed to fall with constant speed. What must be the value of constant speed ?

Options

A. g/b
B. b/g
C. bg
D. b

Answer

A

Explanation

Here, a = g - bv
When an object falls with constant speed `v_c`, its acceleration becomes zero. `therefore g - bv_c = 0` or `v_c = g/b`