Problema Solution
a toy rocket is shot vertically upward from the ground. its distance in feet from the ground in (t) seconds is given by s(t)= -16t^2 +160t. at what time or times will the rocket be 112 ft from the ground?
Answer provided by our tutors
s(t) = -16t^2 + 160t
Set s equal to 112 feet.
s = -16t^2 + 160t = 112
-16t^2 + 160t = 112
-16t^2 + 160t - 112 = 0
t^2 - 10t + 7 = 0
Use the quadratic formula.
(10 +/- sqrt(-10^2 - 4*1*7)/2*1
t = 9.36, 0.64