SOLUTION: If an object is propelled upward from a height of s feet at an initial velocity of v feet per​ second, then its height h after t seconds is given by the equation h= -16^2 +

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: If an object is propelled upward from a height of s feet at an initial velocity of v feet per​ second, then its height h after t seconds is given by the equation h= -16^2 +       Log On


   



Question 1014570: If an object is propelled upward from a height of s feet at an initial velocity of v feet per​ second, then its height h after t seconds is given by the equation
h= -16^2 + vt +s,
where h is in feet. If the object is propelled from a height of
8
feet with an initial velocity of
96
feet per​ second, its height h is given by the equation
h= -16t^2+96t+8.
After how many seconds is the height
148
​feet?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If an object is propelled upward from a height of s feet at an initial velocity of v feet per​ second, then its height h after t seconds is given by the equation
h= -16^2 + vt +s, where h is in feet.
If the object is propelled from a height of 8 feet
with an initial velocity of 96 feet per​ second,
its height h is given by the equation: h= -16t^2+96t+8.
After how many seconds is the height 148 ​feet?
:
We can write the equation:
-16t^2 + 96t + 8 = 148
-16t^2 + 96t + 8 - 148 = 0
-16t^2 + 96t - 140 = 0
simplify, divide by -4
4t^2 - 24t + 35 = 0
solve for t using the quadratic formula; a=4; b=-24; c=35
Two solutions
t = 2.5 seconds to reach a height of 148 ft on the way up
and
t = 3.5 seconds to descend to 148 ft on the way down
+graph%28+300%2C+200%2C+-4%2C+8%2C+-20%2C+200%2C+-16x%5E2%2B96x%2B8%2C+148%29+
looks like this graphically, green line is 148ft