A ball is thrown across a playing field from a height of h = 5 ft above the ground at an angle of 45 to the horizontal at the speed of 20 ft/s. It can be deduced from physical principles that the path of the ball is modeled by the function
y = (32/(20)^2)x^2 + x + 5

where x is the distance in feet that the ball has traveled horizontally.

(a) Find the maximum height attained by the ball. (Round your answer to three decimal places.)
Answer: 8.125 (I found (a), but i can't do question (b).)

(b) Find the horizontal distance the ball has traveled when it hits the ground. (Round your answer to one decimal place.)

Question

A ball is thrown across a playing field from a height of h = 5 ft above the ground at an angle of 45 to the horizontal at the speed of 20 ft/s. It can be deduced from physical principles that the path of the ball is modeled by the function
y =  (32/(20)^2)x^2 + x + 5

where x is the distance in feet that the ball has traveled horizontally.

(a) Find the maximum height attained by the ball. (Round your answer to three decimal places.)
Answer: 8.125 (I found (a), but i can't do question (b).)

(b) Find the horizontal distance the ball has traveled when it hits the ground. (Round your answer to one decimal place.)

coconutjj · Answer

can you write the equation in written form not ascii form, it's very confusing

anonymous · Answer

$$y=-\frac{ 32 }{ (20)^2 }x ^{2}+x+5$$

freckles · Answer

Calculus (find y' first and the the critical numbers)
Algebra(find the vertex of the parabola)

anonymous · Answer

How would I do part b?

freckles · Answer

So that means h=0
and h is represented by y

freckles · Answer

$$0=\frac{-32}{20^2}x^2+x+5$$

freckles · Answer

find x-intercepts
only want ones where x>0