Answer
$Speed=\left| v\right| =\left| -64\right| =64\dfrac {ft}{s}$
Work Step by Step
$v\left( a\right) =\lim _{t\rightarrow a}\dfrac {s\left( a\right) -s\left( t\right) }{a-t}\Rightarrow v\left( 2\right) =\lim _{t\rightarrow 2}\dfrac {\left( 500-16\times 2^{2}\right) -\left( 500-16\times t^{2}\right) }{2-t}=\dfrac {16\left( t^{2}-2^{2}\right) }{2-t}=\dfrac {16\left( t-2\right) \left( t+2\right) }{-\left( t-2\right) }==-16\left( t+2\right) =-16x\left( 2+2\right) =-64 $
Question asked how fast paint will go so
$Speed=\left| v\right| =\left| -64\right| =64\dfrac {ft}{s}$