Erin and her friends launch a rocket from ground level vertically into the air with an initial velocity of 80 feet per second. The height of the rocket, h(d, after t seconds is given by
h(t) = -16t2 + 80t
1. They want to find out how high they can expect the rocket to go and how long it will be in
the air.
a. Use the coordinates for the vertex of the path of the rocket to find t, the number of
seconds the rocket will be in the air before it starts its downward path.
b. Find the maximum height of the rocket.
c. What are the coordinates of the y-intercept and what do they represent in the context of
this problem?
I
d. Megan points out that the rocket will have a height of zero again when it returns to the
ground. How long will the rocket stay in the air? Explain how you found your answer,