Question

If a football player passes a football from 4 feet off the ground with an initial velocity of 36 feet per second, how long will it take the football to hit the ground? Use the equation h = -16t^2 + 6t +4. Round your answer to the nearest hundredth.

Answer 1

t = 0.722 seconds

Explanation:

Given in the question that an equation

h = -16t² + 6t + 4

here h is the height

t is the time

To solve this question we need to substitute height with zero because at ground level height is zero

h = 0

0 = -16t² + 6t + 4

a = -16

b = 6

c = 4

Formula to use

t = -b±√(b²-4ac) / 2a

Plug values in the formula

t = -6 ± √36-4(-16)(4) / 2(-16)

t = 6±2√73 / 32

t = 6+2√73 / 32 or t = 6-2√73 / 32

t = 0.722 or t = -0.347

since time can't be in negative so we reject t = -0.347