Answer:
2.0
Step-by-step explanation:
[tex]when \: the \: object \: hit \: the \: ground \: \\ h(t) = 0 \\ - 4.9 {t}^{2} + 5t + 9 = 0 \\ a = - 4.9 \: \: b = 5 \: \: c = 9 \\ x = \frac{ - \: b \: - \sqrt{ {b}^{2} - 4ac} }{2a} \\ x = \frac{ - \: 5 \: - \: \sqrt{ {5}^{2} - 4( - 4.9) \times 9} }{2( - 4.9)} \\ x = \frac{ - \: 5 \: - \sqrt{25 + 176.4} }{ - 9.8} \\ x= 2.0[/tex]
