I can't understand why buoyant force exerted by the liquid on a ball attached to a rope in a box having liquid of density $p$ moving in an elevator moving with acceleration $a$ has buoyant force as,
$B= Vp(g+a)$ (V is the volume immersed ,i.e. the volume of ball itself)
Why its not $B=Vpg$ ? Please try explaining mathematically/by using equations please.