Question

ALGEBRA 1, SEMESTER 2- please help, im failing my class already

A model rocket is launched from the ground with an initial velocity of 80 feet per second. The height of an object h, in feet, after t seconds, with initial velocity v0 and initial height h0 is given by h(t)=−16t2+v0t+h0 .

What is the approximate maximum height the rocket reaches?

Answer 1

Velocity is given as 80 feet per second, so replace V with 80.

The rocket is launched from the ground so the initial height is 0, so replace h with 0

The formula now becomes" h(t) = -16t^2 + 80t +0

To find the maximum we need to find the coordinates of the vertex by finding the axis of symmetry:

-b/2a = -80/(2*-16) = -80/-32 = 2.5

This represents the amount of time for the rocket to reach maximum height.

So we now replace t in the equation with 2.5 and solve for the height:

h(2.5) = -16(2.5)^2 + 80(2.5)

h(2.5) = 100

The maximum height is 100 feet