A particle is thrown upwards from ground. It experiences a constant air resistance force which can produce a retardation of 2 m/s2. The ratio of time of ascent to thetime of descent is

Let a be the retardation produced by resistive force, ta and td be the time ascent and descent respectively.If the particle rises up to a height h Then h=12(g+a)ta2 and h=12(g−a)td2∴ tatd=g−ag+a=10−210+2=23