Solving a word problem using a quadratic equation with irrational functions

Question

A ball is thrown from an initial height of 6 feet with an initial work velocity of 18 feet/S. The balls height age, parentheses, and feet parentheses after T seconds is given by the following. H equals 6+18 T -16 T to the second power. Find all values of T for which the balls height is 10 feet. Round your answer to the nearest hundred.

Answer 1

h(t) = 6 + 18t - 16t² = 10; 16t² - 18t + 4 = 0; t = (9 ± √81 - 64)/16 = (9 ±√17)/16; t = 0.305 s or t = 0.82 s