Question

A soccer ball is kicked into the air. Its height above the ground can be approximated

by using the equation h = -3t2 + 15t, where h is the height above the ground in
meters and t is the time in seconds.
a) What are the zeros of this relation?
b) When does the ball hit the ground?
c) When does the ball reach its maximum height?
d) What is the maximum height of the ball?

Answer 1

See below in bold.

Explanation:

a) h = -3t^2 + 15t = 0

-3t(t - 5) = 0

t = 0, 5 are the zeroes of the relation.

b) The ball hits the ground when h = 0 so it is after 5 seconds.

c) The path of the ball is a parabola which opens downwards so the maximum height is when x = 5/2 = at 2.5 seconds.

d) this maximum height is -3(2.5)^2 + 15(2.5) = 18.75 meters.