Question

Rebekah kicks a soccer ball off the ground and in the air, with an initial velocity of 25 feet per second. Using the formula H(t) = −16t2 + vt + s, what is the maximum height the soccer ball reaches? 9.5 feet 9.8 feet 10.2 feet 10.7 feet

Answer 1

A: 9.8

Explanation:

took the test

Answer 2

h(t)=-16t^2+25t

The maximum height occurs at the vertex of the quadratic.

The vertex of a quadratic is always at:

(x,y)=(-b/(2a), (4ac-b^2)/(4a))

So the maximum height is:

(4ac-b^2)/(4a), and in our equation a=-16, b=25, and c=0 so

hmax=(0-25^2)/(-64)

hmax=-625/-64

hmax=9.765625

hmax≈9.8 ft (to nearest tenth of a foot)