Answer:
the object will attain maximum height at 3.5 seconds.
Step-by-step explanation:
The height of the object (in feet), h, above the ground t seconds after it is fired is given by h(t)=−16t2+112t+128.
128 represents 128 feet above the ground and this is the height from which the object was fired.
The given equation is a quadratic equation and plotting of this equation on a graph would give a parabola whose vertex would be equal to the maximum height travelled by the rocket.
The vertex of the parabola is calculated as follows,
Vertex = -b/2a
From the equation,
a = -16
b = 112
Vertex = - - 112/32= 3.5
So the object will attain maximum height at 3.5 seconds.
