we are given
position function as
[tex]s(t)=-16t^2+20t+100[/tex]
Since, we have to find velocity
so, we will find derivative with respect to t
[tex]s'(t)=-16*2t+20*1+0[/tex]
[tex]s'(t)=-32t+20[/tex]
[tex]v(t)=-32t+20[/tex]
now, we can plug t=1
[tex]v(1)=-32*1+20[/tex]
[tex]v(1)=-12ft/sec[/tex].................Answer