The equation below is in the form $h = a t ^ { 2 } + b t + c$ The input is the time t, in seconds. The output is the height h of an object tossed straight up from a height c, in feet, with an initial velocity b, in feet per second. $- 16 t ^ { 2 } + 25 t + 60 = 0$ Solve the equation for t, using the quadratic formula. Round to the nearest hundredth. Which answers are acceptable in the setting?
A) $t = 2.87 \mathrm { sec } , \text { discard } t = - 1.31$
B) $t = 1.48 \mathrm { sec } , \text { discard } t = - 2.87$
C) $t = 1.52 \sec , \text { discard } t = - 1.48$
D) $t = 2.87 \mathrm { sec } \text {, discard } t = - 1.48$
E) no real number solution

Question

Quizplus · Accepted Answer

The quadratic formula is $\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$, where $a = -16$, $b = 25$, and $c = 60$. Substituting these values gives two solutions, but only the positive one, $t = 2.87$ seconds, is physically meaningful because time cannot be negative.

The Equation Below Is in the Form h=at2+bt+ch = a t ^ { 2 } + b t + ch=at2+bt+c

The Equation Below Is in the Form $h = a t ^ { 2 } + b t + c$