A beachball is tossed from the top of a swimming pool sliding board. The formula

h $=4\mathrm{.}9$t$2+8\mathrm{.}6$t $+5\mathrm{.}875$

can be used to determine the height h in meters of the beachball at time t in seconds after it is released. When will the beachball hit the pool water $($in seconds$)?$ Round to the nearest tenth.