Question 84919
when the object hits the ground, s is 0 ... 0=-16t^2+176t+112 ... dividing by -16 gives 0=t^2-11-7


quadratic formula gives {{{t=(11 +- sqrt((-11)^2-4*1*(-7)))/(2*1)}}} ... {{{t=(11 +- sqrt(149))/2}}}


t=11.6 and t=-0.6 ... negative value is not realistic