A container with mass m kg is dropped by a helicopter from
height h km at time t=0, with zero velocity. from the outset, its
fall is controlled by gravity and the force of air resitance, f(v)=
-kv, where v is the current velocity of the container. in t seconds
after the drop, a parachute opens, resulting in an increase of air
resistance up to f(v) = -kv. determine the time t at which the
container touches the ground. and...