Question 605635
The equation looks wrong. It should be
{{{ d(t) = -16t^2 + 2t + 560 }}}
{{{ d(5.5) = -16*5.5^2 + 2*5.5 + 560 }}}
{{{ d(5.5) = -16*30.25 + 11 + 560 }}}
{{{ d(5.5) = -484 + 571 }}}
{{{ d(5.5) = 87 }}}
The rock will be 87 ft off the ground in 5.5 sec