[" A particle is thrown upwards from ground.It "],[" expertiences a constant air resistance force "],[" which can produce a retardation of "2m/s^(2)],[" The ratio of time of ascent to the time of "],[" descent is: "],[" descent is: "],[" (2."1:1],[" (2) "(2)/(3)],[" (2) "(2)/(3)],[" (2) "sqrt((3)/(2))]