how to make "grass" disperse

alright…so im trying to take something ive made and put it in grass to make it a bit better looking…but i have a few problems and questions…
1-lets say i have a cube and when i put it into the grass nothing happens to the grass…wat if i want it to spread around it like real life…(do i have to “comb” it manally??)
2- if im gonna have wind in my little animation how do i make the grass move with the wind?
3-why does my computer lag when i have anywhere more the 15000 hair strands…(is it really because of my computer…cause my frined has almost the same specs but his doesnt lag…):confused:…sorry for yet another thread on grass…

blender spartan

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