Question 446304
A projectile is fired upward from a tower 300 feet high with an initial velocity of 320 feet per second.
 Its height above ground(h feet)is given at any time(t seconds) by the equation: h=-16t^2+320t+300.
 How many seconds will it take the projectile to reach its maximum height?
 :
Use the axis of symmetry formula to find the time for max height: x=-b/(2a)
t = {{{(-320)/(2*-16)}}}
t = {{{(-320)/(-32)}}}
t = +10 seconds it will be at max height
:
What is that maximum height?
Replace t with 10 in the original equation
h = -16(10^2) + 320(10) + 300
h = -1600 + 3200 + 300
h = 1900 ft is the max height