The value for which the ball's height is 28 feet are 0.817sec and 1.683sec using quadratic equations.
What is a quadratic equation?
ax^2 + bx + c = 0
where x represents an unknown, and a, b, and c represent known figures, where a ≠ 0. is still, not quadratic, as there's no ax^2 term,( If a = 0( and b ≠ 0) also the equation is direct.)
Given,
h(0)=6 ft (six)
v(0)=40 ft/sec (fourty)
h(t)=6+40t-16t2 (equation)
for h=28 ft(twenty eight)
28=6+40t-16t2 (equation)
or 16t2 - 40t + 22 = 0 (equation)
or 8t2 - 20t + 11= 0(equation)
on solving the quadratic equation
t=0.817sec and 1.683sec (answer)
Learn more about quadratic equations here: https://brainly.com/question/1214333
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