1.There is a falling object, whose mass is A[kg] and experiences a force (its own weight) equal numerically to A=(7) times 9.81. The object starts from rest and the air causes a retarding force numerically equal to B=(0.2) times its velocity. a)Find general expression for velocity as a function of time, and draw its graph. b) Evaluate velocity for t=C ( s ) the value of C is 5.