Question

somebody please help me find the solution totally lost....

An object of mass 100g is thrown vertically upward from a point 60cm above the earths surface with an initial velocity of 150cm/sec. It rises briefly and then falls vertically to the earth, all of which time it is acted on by air resistance that is numerically equal to 200v (in dynes), where v is the velocity (in cm/sec).

a) find the velocity 0.1sec after the object is thrown.

b)find the velocity 0.1sec after the object stops rising and start falling.