Question 829633
{{{h(t)=160t-t^2}}}
The rocket is on the ground when h(t) = 0
so solve {{{160t-t^2=0}}}
{{{-t^2+160t=0}}}
multiply by -1
{{{t^2-160t=0}}}
factoring
{{{t(t-160)=0}}}
So solutions for when the rocket is on the ground are 0 and 160
The rocket is back on the ground in 160 seconds.

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