Question 1073425
(a)
5.04 seconds


b)
{{{-16t^2+80t+3>76}}}
{{{-16t^2+80t-73>0}}}
{{{16t^2-80t+73<0}}}
time between the roots...


These roots, {{{(80+- sqrt(12*12^2))/32}}}


{{{(80-12*sqrt(12))/32}}} from {{{(80+12*sqrt(12))/32}}}

{{{(24*sqrt(4*3))/32}}}

{{{48sqrt(3)/32}}}

about 2.5 seconds