an object thrown vertically upwards into the air takes shorter time to reach its peak height than it does to return to the height of the throw, is this true, how can it be, on the way up it has both the airs resistance ang gravity working against it whereas on the way down only the resistance, is the speed of the object necessarily the same when it passes the beginning point on its descent as it was when it was thrown(Vo=Vf)? even in a case where air resistance is taken into account? if so i think i understand, - because the acceleration is lesser on the descent(because the forces are working in opposite directions) the time is greater. is this correct? how can i summarise this using the equations of work and energy?