Question : The motion of a body falling from rest in a resistive medium is described by the equation 𝑑𝑣/𝑑𝑡= 𝑎 − 𝑏𝑣, where 𝑎 and 𝑏 are constants. The velocity at any time 𝑡 is
(A) \left( a-b^{2t}\right)
(B) \dfrac{a}{b}\left( 1-e^{-bt}\right)
(C) abe^{-t}
(D) ab^{2}\left( 1-t\right)
Answer : option (B)
Solution :
