Final answer:
The best representation of Speedy's height as a function of time in a quadratic equation is option B: h(t) = 70t - 14t², which accounts for initial velocity and acceleration due to gravity.
Step-by-step explanation:
The best representation of the quadratic function modeling Speedy's height, h(t), as a function of elapsed time, t, is one that takes into account initial velocity and acceleration due to gravity when modeling projectile motion. Typically, the height of an object in free fall is represented by a quadratic equation in the form h(t) = -at² + bt + c, where 'a' is the acceleration due to gravity (negative because gravity pulls the object down), 'b' is the initial velocity, and 'c' is the initial height.
In the options provided, the one that reflects the effect of gravity and possible initial upward velocity is option B: h(t) = 70t - 14t². This equation suggests that Speedy has an initial upward velocity (from the positive linear term 70t) and is being acted upon by gravity causing the height to decrease over time squared (from the negative quadratic term -14t²).