1)

The solution of  dvdt+kmv = -g is


A) v=cˉekmtmgk

B) v=cmgkˉekmt

C) vkmt=cmgk

D) vkmt=cmgk

Answer:

Option A

Explanation:

dvdt+kmv = -g → dvdt=km(v+mgk)

dvv+mg/k=kmdt

log(v+mgk) = kmt+log c

(v+mgk)=Cektm

v=Cˉekmtmgk