Accepted Answer
we an assume her that marble is project with horizontal velocity=2neglect air resistanceit falls a distance 1mit vertical velocity initially is 0so 1=1/2gt^2i take g=10then we find that t=0.2236 s
we an assume her that marble is project with horizontal velocity=2neglect air resistanceit falls a distance 1mit vertical velocity initially is 0so 1=1/2gt^2i take g=10then we find that t=0.2236 s