Question

David, a platform diver, dives into the pool during practice. The height of David above the water at any given time, s, can be modeled by the quadratic function h(s).

Each of the following functions is a different form of the quadratic model for the situation above. Which form would be the most helpful if attempting to determine the time required for David to enter the water?

A. h(s) = -4.9(s - 2)(s + 1)

B. h(s) = -4.9s(s - 1) + 9.8

C. h(s) = -4.9(s - 0.5)2 + 11.025

D. h(s) = -4.9s2 + 4.9s + 9.8

Answer 1

Check the pictures below.

if we knew the roots/solutions of the equation, we can set h(s) = 0 and solve for "s" to find out how many seconds is it when the height is 0.

if you notice in the first picture, when f(x) = 0, is when the parabola hits a root/solution or the ground, for David he'll be hitting the water surface, and the equation that has both of those roots/solutions conspicuous is

h(s) = -4.9(s - 2)(s + 1).